Diamanti | Categoria | gioiellis.com

How to distinguish between real and synthetic diamond?

Published on January 3, 2024

Mr Big regala l'anello con diamante nero a Carrie Bradshaw in «Sex and the City»

Attention: the number of synthetic diamonds is increasing, which are now even produced by De Beers. Do you know how to recognize laboratory-created diamonds? The first thing to know is… ♦

How do you know if the diamond in your ring is synthetic? Is it possible to find out if a diamond is real or fake? The answer is: it depends. The difference is not visible to the naked eye, but only with sophisticated instruments. Naturally, a diamond is considered fake only if its origin is not declared. Synthetic diamonds, if they are officially declared as such, cannot be considered fake. Lastly, diamond giant De Beers has also entered the scene, producing synthetic diamonds with a laboratory in Great Britain for jewelery under the Lightbox brand.

Orecchini lab-grown di Lightbox — Lab-grown earrings by Lightbox

The misunderstanding between real and synthetic, however, is a problem for traders: in fact, in case of doubt, for large stones traders turn to gemological institutes. But if the certifications are dubious, large jewelers do not use smaller stones, under 1 carat, to avoid the risk of compromising their reputation. Alberto Osimo, diamond wholesaler and president of the Geci (Gemological Education Certification Institute) of one of the main gem laboratories in Italy, stated this some time ago: «Currently there is only one machine, the Diamond view, produced by Dtc, the Diamond trading company, able to carry out this analysis, which however takes ten minutes and is uneconomical in the case of diamonds of one hundredth of a carat. In fact, it is not convenient to certify and check a stone worth just a few euros when the procedure could cost up to 80 euros per piece.” However, other systems subsequently proposed to analyze diamonds also require long and expensive procedures.

By Ethereal Green Diamond, 34,59 ct. Photo: Johnny (Chak Wan) Leung — By Ethereal Green Diamond, 34,59 ct. Lab-grown diamond. Photo: Johnny (Chak Wan) Leung

A partial solution to the problem comes from another machine created by the Swiss institute Ssef and capable of analyzing even 4 thousand stones in a single hour. So everything is fine? In part: the device only identifies the molecular structure of the object, i.e. it divides them according to type. And, fortunately, only one of these categories is artificially replicable. In short: a synthetic diamond can only be identified with expensive machines and complicated procedures.

Expertise in un laboratorio Tiffany — Expertise in a Tiffany laboratory

But it’s not just synthetic diamonds. Alongside the natural diamond, there are laboratory-created stones on the market, such as cubic zirconia and synthetic moissanite. Which are certified and sold as extremely cheaper alternatives to diamonds which are the result of the thousand-year-old work of the earth.

So, how do you know if your diamond is real or fake?

1 A real diamond is certified. Therefore, a diamond jewel must also have the certificate attesting its purity, color and carats.

2 You can purchase a device to test yourself. A device such as the Professional Diamond Selector I. It is a probe or thermal conductivity meter and can be found on sale on Amazon for a few dollars, serves to distinguish real diamonds from other simulated stones. For example, it finds out whether the stone is, in fact, a crystal or a cubic zirconia. However, he will not be able to find out if the diamond was created in a laboratory.

3 Other tests that you can do at home: drop the diamond into a glass full of water (but this presupposes that it is separated from the jewel). If the gemstone sinks it is a real diamond. If it floats on the surface of the water or just below it, it is false.

4 Breath test: fog the diamond with your breath, as if cleaning the lenses of your glasses. If the water vapor dissolves immediately from the surface, the diamond is more likely to be authentic. Needless to say, it’s a very crude method…

5 Take a magnifying glass. If you see the tiny abbreviation CZ on the stone it means that it is cubic zirconia.

6 A test for strong hearts: heat your diamond on a flame for 40 seconds. Then throw it in a glass of cold water: if it’s real it won’t break. But if it’s a crystal… We don’t recommend it, if you want to try it’s your risk.

Controllo del reattore al plasma CVD che produce diamanti in laboratorio — Control of CVD plasma reactor producing diamonds in De Beers laboratory

Turn your husband (or dog) into a diamond

Published on February 27, 2023

news/Diamanti

How about turning your dead dog or cat into a diamond? What if wuould be your husband or wife to leave you? A company proposes, for all of them, to keep the precious memory of the companions of many years: transform them into jewels. The idea, unsurprisingly, was born in the USA, where years ago a company decided to inaugurate the business of transforming deceased relatives, or domestic animals, into synthetic diamonds. The company is called LifeGem and is based in Chicago. Its activity consists in transforming the cremated remains into wearable gems, transforming the carbon contained in the ashes into (macabre) artificial diamonds. The cost depends on how many carats you want to get from the ashes. It starts at around $ 2,000 to go up to almost $ 20,000. Prices are lower for animals.

An operation that, they point out with discretion, has often been adopted for human beings: the idea of slipping the mother-in-law on the finger, in fact, for some women might sound like an attractive revenge. “Once captured, the carbon is heated to extremely high temperatures in particular conditions. In removing the ash, the process eliminates the carbon from the former house dog and with the help of our technology turns it into a diamond,” they explain to LifeGem . The service was launched in 2002. Since then customers can choose between gems of different colors, cuts, and select the setting for a pendant or a ring.

Mind you, it’s not a cheap souvenir. But, it seems, over six thousand persons have already asked to transform their dears, and bodies of cats, dogs, rabbits, horses and even an armadillo, into expensive trinkets. Like Katie Pilon, from Boston, who now wears her Meowy, a beloved cat who has been transformed into a beautiful blue blue diamond.

In truth, the company’s practices have been questioned, and some have questioned the seriousness of LifeGem. Rejected objections: “Kenneth Poeppelmeier, professor of chemistry at Northwestern University, has argued that there is no reason why the process should not work, and Avrum Blumberg, professor of chemistry at DePaul University in Chicago, admitted that it is possible to do a high quality diamond from the carbon contained in a cremated human being, “supporters retort.

Diamante sintetico dopo il taglio e la lucidatura

However, it is impossible to distinguish the origin of synthetic diamonds which, therefore, could have originated from ordinary graphite instead of from the remains of the pet. But, basically, it doesn’t matter: what better memory than being associated with a diamond, which is forever?

Jennifer Lopez’s extremely rare green diamond

Published on October 1, 2022

Campus/Diamanti

L'anello con diamante verde ricevuto da Jennifer Lopez

Green diamonds are very rare and very expensive. Because they have a secret ♦ ︎

Colored diamonds have inflamed Sotheby’s and Christie’s auctions for many years. While colorless diamonds, commonly called white, were once the most expensive gems, now it is the colors that are paid the most. The most popular colors are yellow, pink and blue. Rarer are red diamonds. But there are also diamonds of another color, even rarer: they are the green ones. Extremely rare. One of the few women to have a green diamond in the drawer (but perhaps in the safe) is Jennifer Lopez, who received it as a gift, mounted on a ring.

L'anello con diamante verde di Jennifer Lopez — L’anello con diamante verde di Jennifer Lopez

Because they are green. The green color is extremely rare in diamonds also because it is also believed to be due to the exposure of the stone to radioactive materials. But do not worry: you can wear them without problems. Green diamonds were near, millennia ago, small amounts of material such as uranium or thorium. But over time, radioactivity has declined, that is, it has ceased. In any case, these radiations penetrated the nearby diamond crystal and changed its color.

Anello con un raro diamante verde e diamanti bianchi — Anello in platino con un raro diamante verde e diamanti bianchi

Artificial green. Since green diamonds are the result of radiation, why not repeat the process in the laboratory? It is, in fact, what some laboratories do to produce a green color in diamonds. The stones are polished and then hit with a low-energy electron beam. With this same system, yellow diamonds are produced. Another method is to apply a thin layer of silica on the surface of the diamonds. But, beware: the coating is very thin and can be lost with normal wear.

Aurora Green, venduto da Christie's per 16,8 milioni di dollari, record d'asta mondiale — Aurora Green, venduto da Christie’s per 16,8 milioni di dollari, record d’asta mondiale

The biggest. The diamond called Green Dresden is the largest in the world (40.72 carats) with this shade. It is kept inside the Dresden castle. The ring you see in these images, however, was sold for $ 1.8 million in the spring of 2014. Its assessment is also due to the fact that the jewel is signed by the legendary designer Jar. The colored limestone diamond mounted on the ring weighs 2.49 carats and is set on platinum, surrounded by colorless diamonds. Also interesting to remember the story of this stone: once belonged to Countess Eliza Branicka Krasińska and was mounted on her engagement ring with the romantic poet Count Zygmunt Krasinski, in Poland. The two married in 1843 and remained together until the count’s death in 1859.

Il Verde di Dresda, custodito nel castello della città

Un raro diamante verde contornato da bianchi e fancy pink

Diamante verde montato su anello firmato Jar. Venduto per 1,8 milioni di dollari nel 2014

La scala delle tonalità dei diamanti verdi

Romano Diamonds, design in Milan

Published on September 28, 2022

Rings/Diamanti/Showroom/COLLANE

Anello Quinology con cinque diamanti taglio brillante

The jewels of Romano Diamonds, a Milanese company that continues the tradition of design ♦ ︎

It is not unusual for a gemstone merchant to skip the fence and try to take on the clothes of his customers. This was also the case for Marco Romano, founder of Real Diamond Invest, and Nicoletta Bonzano, an expert gemologist. Real Diamond Invest has been active for years in the international diamond trading market, between Tel Aviv, Mumbai and Antwerp. Therefore, the raw material is available: quality gems. Thus Romano Diamonds, which is based in front of Milan’s Castello Sforzesco, was born from the trading company.

The style of jewelry is quite varied. It includes the classic solitaire ring or light points to put on the neck, but also more modern shapes, with cluster or pavé diamonds, pink or white gold with often quite soft volumes. But not the Zip collection, which features baguette-cut or emerald-cut diamonds that are surprisingly aligned in a cross line. To reach a high quality standard, Romano Diamonds entrusts the realization of jewels to the goldsmiths of Valenza, a guarantee.

Collana della collezione Quinology con 5 diamanti taglio brillante

Orecchini della collezione Quinology con diamanti taglio brillante

Anello della collezione Moonlight in oro rosa e pavé di diamanti

Orecchini Karma con diamanti per 3,62 carati

Anello della collezione Brick in oro rosa e 10 diamanti baguette, 5 diamanti taglio smeraldo

Anello con 28 diamanti taglio radiant, 14 diamanti taglio smeraldo

Eva Fehren, luxury and simplicity

Published on July 25, 2022

Showroom/Diamanti/Rings

The jewels in black and white (with a pink and yellow) by Eva Zuckerman, designer of Eva Fehren, who won a Couture Awards: essence of New York ♦ ︎
The world is divided into two: those who love color photos and those who appreciate those in black and white. There are two schools of thought, both of them with good reasons, which also meet in jewelery. There are those who draw only wondrous collections of colored stones and elaborate shapes, and those who prefer simplicity. Among the latter, who are standard bearers of minimal philosophy, is the super New Yorker Eva Zuckerman, who founded Eva Fehren and won the Best in Bridal at Couture Awards 2018. Why super New Yorker?

Private ring in oro bianco annerito e diamanti

Because she not only emphasizes that she was born and lives in the skyscrapers, but also has her roots in a precinct Manhattan neighborhood, the East Village. She was born, grown and lived, in short, close to those tall buildings that throw net shadows on the ground. And perhaps this is her source of inspiration: her jewels are agile, with net forms, with no superfluity. Most are also in black and white: dark gold, white diamonds or vice versa. With time it has expanded her offer also to jewelry in pink gold and stones, but always without abandoning its monochrome philosophy, in a perfect mood recalling Woody Allen’s films.

Orecchino a bottone in oro bianco annerito e diamante

New geometries of Etho Maria

Published on June 20, 2022

Rings/Diamanti/Showroom/COLLANE

Orecchini in oro giallo, diamanti, ceramica

The new uncompromising geometries of Etho Maria, a maison that combines ceramic and diamonds ♦

Born in the home of philosophy, Athens, Etho Maria has chosen the philosophy of luxury with a bit of surprise. The Maison, which from Greece soon expanded to the rest of Europe and the USA, is anchored to the idea of jewelery with much geometry. Not by chance Euclid and Archimedes was not Greek. Geometry, but precious. And surprising. Like when Etho Maria presented a collection that combines red ceramic with sparkling white diamonds. No doubt a combination that has remained in the memory. The idea, among other things, has earned awards such as the Diamond Classic at the Centurion Design Awards 2018 and the Editor’s Choice at the 2017 Centurion Design Awards in Scottsdale, Arizona.

Bracciale in oro con diamanti marquise e ovale, con tocchi di smalto

In addition to red ceramics, the Maison has also decided to use the ceramic-diamond pair also with other colors, like white. The effect always works. Alongside this series of jewels that use an innovative aesthetic to an equally refined goldsmith technique, the Maison offers more traditional jewels, but always with a design that does not forget the modern style which, for example, does not omit stones cut with the shape of the triangle. Jewels that have been chosen by luxury chains, such as Neiman Marcus or Saks Fifth Avenue for ad hoc sales.

Orecchini in oro bianco con zaffiri blu e lapis

Orecchini pendenti in oro bianco con zaffiri blu e diamanti

Anello in oro giallo, diamanti, ceramica

Collana con zaffiri verdi e diamanti brown — Collana in oro con zaffiri verdi e diamanti brown

Collana in oro rosa con zaffiri blu e diamanti

Diamonds: rules to avoid scams

Published on June 16, 2022

Campus/Diamanti

Are you sure of the origin of the diamond on your ring? And if you have to buy a diamond ring (or another jewel), how do you know if what you buy is authentic? In other words: how do you avoid scams when buying a diamond? Here are four useful tips to avoid nasty surprises ♦

Unfortunately, scams or incorrect behavior are also present in the jewelry world. They are quite rare, fortunately. But to avoid falling into a trap you can follow these four rules.

Are you sure that your diamond is really a diamond? The doubt arises after reading a news story that comes from California, taken from Jck. According to the Chronicle, the owner of a jewelry store in Ventura, California town, he was arrested on charges of replacing the diamond of ring to a repair with moissanite. To discover the scam was a woman, who had given the jeweler wedding ring to repair. The damage was estimated at about 8 thousand dollars. Nothing dramatic, sure. But it makes an impression to read on the web a comment to the news: “Unfortunately, I have a great-uncle who is a jeweler in Florida, does the same thing, but uses cubic zirconia”. In short, two clues are not proof, but it raises suspicion: how widespread this type of fraud? Of course, there are cases in which diamonds (fake) are sold (or, rather, passed off) outside of official channels. In Italy, for example, it happened in Sicily and near Lake Garda: in both cases the false jewelers trying to sell fake jewelry to true elders, were arrested.

But how to behave, instead, when you buy a diamond? Here are the rules.
1 The best security is when the diamond is accompanied by a certificate from a gemological institute recognized. For example, Gia (Gemological Institute of America), which is the most credited, or AGS (American Gem Society), IGI (International Gemmological Institute). But it is also good to know that the assessment of a diamond is not the same for everyone. Of course, the authenticity comes first, but then comes into play also the quality and the type of stone (see also Short guide to diamonds). in fact it does not exist, an international standard the same for everyone. There are cases of a diamond with various assessments based on the analysis criterion: when the differences are shades, it is easy that a judgment is something personal.

Un esempio di certificato, quello dell'IGI, Istituto Gemmologico Italiano — Un esempio di certificato, quello dell’IGI, Istituto Gemmologico Italiano

2 Consider the manufacturers who add their own brand as a guarantee: these are laser engravings on the part of the diamond not visible to the naked eye, but which are readable with a microscope. Codes or trademarks are, in fact, a further guarantee, because they certify the origin of the stone. In other words: the traceability of a diamond is important and increases its value.

3 Ask for or take a photo of the diamond mounted on the jewel yourself. It can be a guarantee in case of future disputes. This, of course, can be useful in the case of diamonds of a certain weight: a photograph of tiny stones will hardly be of help, unless you resort to shooting with macro lenses (and you must have some experience). In any case, an image of your jewelry is always useful: for example, it can be provided to the police in case of theft.

4 A certificate (if is true) should reassure the buyer. But in any case the European standards assume direct responsibility and full of the seller, in this case the jeweler, to the customer. Anyone who buys a product, even a jewel, has a right of withdrawal, ie can return it if it does not respond to the features described at the time of sale.

The 6 rings by Jennifer Lopez

Published on April 12, 2022

Rings/Diamanti/bijoux

Jennifer Lopez‘s engagement rings: she has collected six. The most valuable is … ♦ ︎

Is there anything better than a wedding with the man you love? The answer is yes: six engagements are better accompanied by as many precious rings. Or, at least, this is the answer that Jennifer Lopez could give you, who has just announced her new official engagement, with its large diamond ring. Probably JLo is a collector of rings and the rotation of husbands and boyfriends is perhaps due to her desire to get new jewels as a gift.

Jennifer Lopez’s sixth engagement ring, thanks to the comeback of Ben Affleck, was designed and made by Tamara Rahaminov and Nicol Goldfiner, of Rahaminov Diamonds, Los Angeles. The ring has a special diamond: an 8.5-carat natural green gem, set with a white diamond and, surprisingly, on a silver band rather than white gold. Although the choice was probably not made to save money. Green is apparently also JLo’s favorite color. The value? There are those who have estimated the cost of diamonds up to 10 million dollars, because green diamonds are rare and precious but, probably, they cost less. Relatively less, of course.

The previous ring received by the American singer from her ex-boyfriend Alex Rodriguez was instead an emerald-cut diamond of 10-15 carats, with a value of up to 5 million.

L'anello con diamante di Jennifer Lopez — L’anello con diamante per Jennifer Lopez di Alex Rodriguez

The stone that she had given Alez Rodriguez has an emerald cut and the jewel is in Art Deco style. Perhaps not by chance it is very similar to that received by Meghan Markle, the Duchess of Sussex who has considerable popularity (even if the critics are not lacking). In any case, in her first 53 years (which turns on July 24, 2022) JLo received six engagement rings, all of which cost at least six figures.

One of her most precious rings was Harry Winston’s pink diamond that Ben Affleck had previously given her. But the third last ring, also by Harry Winston but this time with an 8.5 carat blue diamond, was very precious: it was estimated that it cost 4 million dollars. It didn’t do much good, though.

La pietra che aveva regalato Alez Rodriguez ha un taglio smeraldo e il gioiello è in stile Art Dèco. Forse non a caso è molto simile a quello ricevuto da Meghan Markle, la Duchessa del Sussex che ha una notevole popolarità (anche se i critici non mancano). In ogni caso, nei suoi primi 53 anni (che compie il 24 luglio 2022) JLo ha ricevuto sei anelli di fidanzamento, tutti costati almeno sei cifre.

Uno degli anelli più preziosi è stato il diamante rosa di Harry Winston che le aveva regalato in precedenza Ben Affleck. Ma anche il terzultimo anello, sempre di Harry Winston ma questa volta con un diamante blu di 8,5 carati, era molto prezioso: è stato stimato che sia costato 4 milioni di dollari. Non è servito a molto, però.

Jlo con il primo marito, Ojani Noa e l'anello di fidanzamento — JLo con il primo marito, Ojani Noa e l’anello di fidanzamento

L'anello di Cris Judd — L’anello di Cris Judd

L'anello di Ben Affleck — Il primo anello di Ben Affleck

L'anello di Marc Anthony — L’anello regalato da Marc Anthony

Hulchi Belluni, new jewels, diamonds and Feng Shui

Published on March 21, 2022

Rings/Diamanti/bracciale/Showroom

Anello in oro rosa 18 carati e diamanti della collezione Cubini

The new jewels by Hulchi Belluni: born in Belgium, they are produced in Italy, but they also have a hint of the Orient ♦

Martine Hul is a diamond pavé specialist. And she couldn’t be otherwise: she lives and works in the heart of the diamond capital, Antwerp, Belgium. She is a professional in the jewelry industry with a long experience behind her. In 2001 she decided to found her own jewelry line under the Hulchi Belluni brand, which sounds Italian. The explanation is there: the word Hulchi derives from the foundress’s surname (Hul) to which is added (chi), which is a reference to Eastern philosophy. Belluni, on the other hand, sounds similar to the Italian words “bella luna” (beautiful moon). Because Italy was also a source of inspiration for the Belgian designer.

Anello in oro rosa e diamanti della collezione Cheri

In fact, among the collections there are also jewelry lines with the Italian name such as Cubini or Funghetti. The Belgian Maison also has another link with Italy: its jewels are in fact made in Arezzo. However, not all pavé diamonds are the same: the formula of setting many small stones next to each other alternates with elaborate shapes in pink, yellow or white gold.

Bracciali e orecchini della collezione Cubini indossati

But that is not all. Because to distinguish the Belgian brand there is also the choice of designing the jewels in line with the principles of Feng Shui. If you don’t know what it is, we quote the definition from Wikipedia: “Taoist geomantic art of China, an auxiliary of architecture, akin to Western geomancy. Unlike this, however, it also takes into consideration aspects of the psyche and astrology. There is currently no scientific proof of his hypotheses. ” But whether you are fascinated by Feng Shui or not, the jewels are certainly real.

Bracciale in oro rosa 18 carati e diamanti della collezione Cubini

Anello in oro rosa 18 carati e diamanti della collezione Funghetti

Orecchini in oro rosa 18 carati e diamanti della collezione Petra

Orecchini in oro rosa 18 carati della collezione Funghetti

The geometries of Melissa Kaye

Published on March 14, 2022

Rings/Design/Diamanti

Anello per tre dita Aria Jane in oro rosa e diamanti

Geometric, rigorous, but pleasant jewels of the New York designer Melissa Kaye ♦ ︎
For ten years Melissa Kaye has been dealing with complicated financial products in the world’s most prestigious business bank, Goldman Sachs. And with a leading role: vice president Credit Derivatives Strategist, after a degree in computer science and engineering at the Mit of Boston. Then, in 2010, Melissa decided to radically change her life and start from scratch, or almost. And so, she returned to school at the Fashion Institute of technology to study jewelery design.

Orecchini in oro 18 carati, diamanti e smalto rosa

Two years later, here the great debut with his luxury jewelry brand. Reaching her goals for many years was the style of work, even in jewelry she applied the same rules of business: creativity combined with a practical sense of business. And she did not abandon completely the scientific teachings learned during the degree, given that his jewels have rigorous forms, with well-defined geometries. Of course, with some poetic license, to avoid excessive rigor.
Gold and diamonds are the most used elements and also determine a price range that goes from about 5,000 to 15,000 dollars, with a top of over 36,000 dollars for a necklace with diamonds for 6.86 carats trillion cut.

Collana Ada in oro giallo 18 carati e diamanti

Anello Aria Fan in oro giallo 18 carati e diamanti

Orecchini Cristina in oro rosa, diamanti e smalto neon pink

Anello a fascia Maya a in oro giallo e diamanti

Bracciale Remi in oro, diamanti e smalto neon blu

The thousand reflections of Henri Daussi’s cushion

Published on March 12, 2022

Diamanti/Rings

Anello con diamante centrale a taglio Henri Daussi Cushion

History and diamonds by Henri Daussi, a name and a guarantee like the city in which it was born, Antwerp ♦ ︎
In Antwerp, diamonds are like baguettes in Paris or oranges in Sicily: an element that is part of the territory and tradition. And in the Belgian city, Henri Daussi Loots was born and grew up. He learned the art of cutting diamonds from his father, who in turn had learned it from his father. After years of experience, Henri became a great diamond master and worked for other diamond makers to cut only their most unique and significant diamonds.

Henri, given both a passion and an exceptional talent for cutting the diamond, was the master craftsman and pioneer. He designed a cutting wheel to cut diamonds more precisely and uniformly. He also innovated the classic cushion cut, with a variation that makes it between 10% and 30% larger and brighter. But above all, he became famous for heart-shaped diamonds: he was the first to succeed with it. From a small company with two employees, its DTC (Diamond Trading Company) has grown to 200 employees.
Competence and passion remained in the Loots family. Today the founder’s grandchildren, Jeff and Kristiaan Loots, lead the Henri Daussi, brand founded 60 years ago. The jewels of the Maison, it is easy to guess, they are all based on diamonds.

Anello a banda con una tripla fila di diamanti

Anello con diamanti Henri Daussi Cushion cut

PEndente in oro bianco con pavé di diamanti

Anello a banda con diamanti bianchi e neri

Diamonds, an Amour with 77 faces

Published on December 18, 2021

Showroom/Diamanti

Anello L'Amour, con diamante Crisscut classic

A diamond with 77 facets: it’s called Crisscut and is mounted in the jewels of the L’Amour collection by Christopher Designs ♦

Love is true love only if it is excessive, right? It is something that involves, that drives us to do great things, to challenge rules and clichés. And, then, why a diamond donated for love should not be in tune with this pleasant madness? Christopher Slowinski must have thought in this way when he founded Christopher Designs, in 1981. Born in Poland, Slowinski has worked as a simple apprentice with master craftsmen even after moving to the United States, in New York. City.

Long story short: he invented Crisscut, a patented diamond cut that increases to 77 the little faces of the stones, instead of the traditional 48. This cut makes it even brighter and more brilliant diamond. The Crisscut was initially applied to the emerald cut, to increase their reflexes. But then Christopher has also extended the concept to other cuts such as the Asscher and cushion until you get to 109 facets in a round stone. But the brilliant Crisscut actually has straight walls 12 and 12 sides and this further increases the brightness. The diamonds have become the L’Amour collection. Which has no limits, of course.

Diamante Crisscut su taglio smeraldo, a 77 facce

Anello con diamanti taglio Asscher e Crisscut

Anello con diamanti taglio L'Amour Crisscut — Anello con diamanti taglio L’Amour Crisscut

Anello con diamante taglio smeraldo Crisscut

La comparazione tra il taglio classico e Crisscut

The jewels (and an extraordinary ring flower shape) by Yair Shimansky

Published on December 12, 2021

Rings/Diamanti/Showroom

Orecchini con diamanti fancy yellow al centro e diamanti baguette bianchi

A couple of years ago, in New York, Vogue Italia organized a reunion of designers sensitive to environmental sustainability for an event entitled The Protagonist. One of the guests was Yair Shimansky. Considered one of the kings of diamonds, Shimansky presented a ring called the Desert Rose, with South African diamonds totaling 24.13 carats, accompanied by 42 tsavorite gems and in the center a crystal of Namibian desert rose, set in gold 18 carats.

The flower is inspired by the Fynbos, the spontaneous vegetation of South Africa. And there is a reason: Shimansky has its headquarters in Cape Town, South Africa, although it has another office-atelier in New York. In addition to being a jeweler, Shimansky also has a diamond cutting and polishing business in Johannesburg. He is, in any case, South Africa’s leading jewelry designer and creator of South Africa’s most iconic diamond ring, the Millennium Diamond Ring, in platinum, which has a classic and modern design. Not only: Shimansky also the author of the Brilliant 10 diamond design, a round brilliant cut stone with 71 facets (usually 57 or 58) developed and patented by Shimansky. This diamond is the only one with balance between fire, brilliance and reflection of 33.33% in each area.

Curiously, Shimansky does not have a family of jewelers or diamond dealers behind him. He was born in Israel in 1967, with a housewife mother and a father in a large shipping company. At the age of 12, he and his family moved to London. Back in Israel, after a series of temporary works he changed his life with the decision to sell diamonds and jewels in Japan. Where, with a difficult internship, he learned the art of cutting and polishing, but also the need for perfection. Finally, he went to South Africa, where his father had moved in the meantime. After a difficult start, with few resources, today Shimansky is one of South Africa’s most popular jewelry brands.

Anello in oro giallo con diamante taglio cuscino

Anello pantera in oro giallo, smeraldi, diamanti

Why are they called diamonds (and 21 more surprising news)

Published on December 11, 2021

Campus/Diamanti

Diamonds, the most known and loved gemstone, hides many secrets: here are 22 of them you need to know ♦ ︎

You know that diamond is the hardest material that exists and it is forever. You also know what the 4 C’s are (and if you don’t know it read here). And you also know that diamonds can also be colored. But there are 22 other amazing aspects of the diamond that you need to know.

1 Do you know why diamonds are called that? The name derives from the ancient Greek word ἀδάμας (adámas), which means unalterable, indestructible, untamed.
2 How long has humanity been searching for and wearing diamonds? According to anthropologists, diamonds were recognized and extracted for the first time in India, between 600 and 300 years ago. Diamonds were found in alluvial deposits along the rivers Penner, Krishna and Godavari.
3 It is well known that the diamond has the maximum hardness. Less known that it also has a high thermal conductivity, that is the aptitude to transmit heat. This is also why diamonds are used in many industrial applications such as cutting and polishing tools.

4 If you can, bring your ear close to a diamond and listen. Well, you need a diamond of a certain size, but know that through this gem the sound passes at the highest speed.
5 Even if diamonds are heat transmission, the gems also has a high electrical resistance. You don’t get thunderstruck through a diamond.
6 Diamonds are hard, but can scratch other diamonds. And this can cause damage to one or both stones. When storing them, make sure that the stones do not collide.

Esame di un diamante a un precedente Dubai Jewellery Show — Esame di un diamante durante Dubai Jewellery Show

7 Another interesting property of diamond: it is chemically inert, ie it does not react with most corrosive substances and also has excellent biological compatibility. No diamond allergy is known (thankfully).
8 Colored diamonds are determined by small defects or impurities inside them. In particular, when the diamond is blue it means that inside it has boron, yellow or brown nitrogen atoms, if it is green it is because it has been exposed to radiation, such as violet, pink, orange or red.
9 Nitrogen, responsible for the yellow and brown color, is by far the most common impurity found in diamonds.

Anello della collezione Cannella, in oro rosa e diamanti brown — Brusi, anello della collezione Cannella, in oro rosa e diamanti brown

10 The diamond also has a high optical dispersion (ability to disperse light of different colors) and for this reason it is so bright.
11 How old are diamonds? Much: most natural diamonds are between 1 billion and 3.5 billion years old.
12 Where do diamonds come from? From the belly of the Earth. Most were formed at depths of between 150 and 250 kilometers in the earth’s mantle and some as deep as 800 kilometers. But today they are found at lower depths, because they have been brought to the surface by volcanic eruptions and deposited in rocks known as kimberlite and lamproiti.

Anello con diamante taglio rotondo di circa 13,70 carati firmato Bulgari

13 You will have heard that diamonds are, in practice, compressed coal. But it’s false. Coal is a material formed from prehistoric buried plants, while most diamonds are much older than the first terrestrial plants. However, it is possible that diamonds can be formed from coal in some particular areas, but the diamonds thus formed are very rare.
14 Would you like to have so many diamonds? Then go into space. Although diamonds on Earth are rare, they are very common in meteorites: about 3% of the carbon found is in the form of nanodiamonds, only a few nanometers (one millionth of a millimeter) large. But, according to astronomers, some extrasolar planets could be almost entirely composed of diamonds.
15 The diamond trade is very concentrated: around 90% of the world’s diamonds are cut and polished in Surat, India.

16 The most precious stones are cut in Antwerp’s cutting and trading centers in Belgium, where the International Gemological Institute is based, in London, in the diamond district in New York, at the Diamond Exchange District of Tel Aviv and Amsterdam.
17 When cutting a rough diamond the weight reduction can be in the order of 50%.
18 Cut a diamond is not easy: the stone can be divided by a single well calculated shot, with a hammer and a pointed instrument. But it is a very risky system. In practice, a precision diamond saw is usually used, which is a more reliable but long system.

19 Colored diamonds are in fashion. But only a few years ago: those browns were a large part of diamond production, but they were used mainly for industrial purposes.
20 Brown diamonds were once not valued on the diamond color scale. But after the development of the Argyle diamond mine in Australia, in 1986, they were considered acceptable gems and used in jewelry.

21 The Argyle mine in Australia, with its 35,000,000 carats (7,000 kg) of diamonds per year, produces about a third of global production of natural diamonds. And 80% of Argyle diamonds are brown.
22 What was the biggest diamond theft? It took place in February 2013 at Brussels airport. The thieves fled with gems worth an estimated 50 million dollars. But later the gang was arrested and some of the diamonds were recovered.

Il diamante The Mirror of Paradise, 52,58 carati, D Color, IF, venduto per 6,5 milioni

A cushion called Kotlar

Published on November 6, 2021

Rings/Diamanti/Showroom

Anello in platino con diamante giallo taglio cuscino

Round, brilliant cut, or marquise, baguette, emerald, briolette … The shapes that a diamond can take are many, even if the most used are four or five. But every now and then a new cut is added, invented by some diamond specialist. One of the most well-known cuts that has been added more recently is, for example, the Asscher cut. But it is not the only one. In the United States, another diamond and jewelry specialist such as Harry Kotlar also introduced a new type of facet a few years ago (in 2003).

This is the Kotlar Cushion, characterized by an exclusive 61-sided cushion cut. The color of the stone used for this processing varies from D to K. The clarity ranges from 1F to S12, the size from 0.70 up to 20 carats. Each Kotlar Cushion bears a laser engraving from the laboratory with its certificate number and logo. The Kotlar Cushion has 61 facets: it is modeled with a specific formula of pavilion and crown angles, with percentages and ratios designed to maximize brilliance and sparkle. It is used for stones from 0.70 to 20 carats.

anello platino diamante — Anello in platino con diamante taglio cuscino

A long story that of Harry Kotlar: escaped from racial persecution, he immigrated to the United States from Germany at the end of the war. He specialized in the diamond trade until he founded the jewelry brand that bears his name. He passed away in 1998 and the company is now run by his nephew David Wiener. But diamonds always remain at the center of the business.

Anello in platino con diamante Kotlar Cushion

Orecchini in oro rosa con diamanti taglio brillante

The diamonds of Samer Halimeh

Published on August 15, 2021

alta gioielleria/Diamanti/Showroom

Collana con diamanti bianchi e fancy yellow

The diamonds and jewels of Samer Halimeh, among the best in the world. So much that sometimes they are too loved ♦ ︎

Samer Halimeh is an American jeweler of Lebanese origin. It is based in New York and is loved by stars like Naomi Campbell, Oprah Winfrey, Elton John and the royal families of Saudi Arabia, Abu Dhabi and Brunei. Precisely the esteem that extends to the East has caused many problems for the jeweler. In fact, some time ago, he sent 44 jewels worth 11.5 million pounds to Rosmah Mansor, wife of the former prime minister of Malaysia, Najib Razak. Which, unfortunately (for him) was not re-elected. Three months after the electoral defeat, the jeweler had not yet received back the jewels, which had not even been paid. An unfortunate case, which ended up in the newspapers.

Apart from this misadventure, Samer Halimeh you can say he is a lucky and talented man. He is famous for his diamonds, and to find the best stones he goes directly to where the mines are, especially in Africa. That was how he discovered and cut the famous Ocean Blue diamond, which gave him world fame. His creations have been auctioned at Sotheby’s and Christie’s, or are worn on red carpet stars. Its clientele spans the world, from Arabia to Western Europe, to Russia and the Far East. Where perhaps he will be more cautious now.

Anello con diamante di 8.25 ct fancy intense pink VVS2

Collier con diamanti fancy yellow e smeraldi

Is it worth buying a diamond born in the laboratory?

Published on August 10, 2021

Diamanti/Campus

The irresistible rise of laboratory diamonds. This is why synthetic diamonds are increasingly popular with jewelry buyers ♦

Would you like to buy a ring with a large 1 carat diamond and pay half the price? Or even 90% less? What if the diamond was not extracted in some Russian or African mine, but produced by a factory and with the same characteristics as the natural ones?

It is the dilemma you will face more and more often. Synthetic diamonds, which companies modestly call “laboratory grown diamonds” or even “off the ground” are now an increasingly widespread reality. According to data collected by the Earther website, industry analyst Paul Zimnisky estimates that they will be 2-3% of the market, but with the percentage it is set to increase. Synthetic diamonds, i.e. laboratory-grown diamonds, are now a widespread industry, especially in China where about half of those in circulation are produced, but mostly used for industrial purposes. Diamonds, in fact, are the hardest mineral that exists and are also used for various uses, for example for cutting machines.

Anello ispirato alle fioriture eterne e alle farfalle danzanti del poetico Giardino Inglese. Lavorato a mano in oro bianco 18k Fairtrade, con 184 diamanti da laboratorio Diamond Foundry, per 6,84 carati

Production is also thriving in the West, where even the largest real diamond industry, De Beers, has started producing artificial stones. And the International Grown Diamond Association (Igda), an association founded in 2016 by a dozen companies active in the sector, now has about 50 members. According to the association, the reasons for the growth of synthetic diamonds are two: the technology allows to lower prices and to obtain diamonds that are difficult to distinguish from natural ones, since they are completely identical and have the same composition as those. natural. In fact, to understand if a diamond is real or artificial, equipment is required that only very few gemmology centers have available. If the stone is not guaranteed (assuming traceability works) a jeweler cannot distinguish a natural diamond from a factory-made one.

Anello in oro bianco e diamante di laboratorio

How they are produced

Not all man-made diamonds are created equal. The more traditional system, introduced half a century ago, involves recreating the same conditions with which diamonds were formed in the bowels of the earth. That is, through enormous pressure and an equally exceptional temperature. This method is called HPHT (high-pressure high-temperature). Diamonds are obtained from a carbon material, for example graphite such as that used for pencils. The graphite is placed in a gigantic mechanical press capable of pressures of 5-6 Gigapascals and subjected to temperatures of around 1,600 degrees Celsius. In short, you have to make a great effort.

Orecchini con diamanti di laboratorio Lightbox di De Beers

The alternative system is completely different: it is called CVD and works through chemical vapor deposition. According to the engineers who developed it, it is a way that recreates the conditions of how diamonds could form in the clouds of interstellar gas in space. In this case, a gas generated from hydrocarbons, such as methane, is pumped into a low pressure reactor next to the hydrogen. The gases are then heated from 3,000 to 4,000 degrees Celsius. This causes the carbon atoms to break, which then settle on a substrate, typically a flat square plate of a synthetic diamond produced by the HPHT method.

Features

How is it possible that engineering and chemistry produce stones that are completely similar to natural ones? Yet it is so. Indeed, the lack of nitrogen in diamonds produced with the CVD method apparently confers exceptional chemical purity. So much so that lab grown diamonds are classified as type IIa, that is particularly pure, as they are only 2% of those found in nature. Among other things, while in the past man-made diamonds were only very small, today producers are also able to create stones of considerable size, always with a high degree of purity. In the USA an artificial diamond of almost 7 carats was produced, but in Germany it has gone as far as to produce a monster of 155 carats.

Anversa: acquisti di un buyer — Antwerp (Anversa): acquisti di un buyer

The price

Years ago a laboratory diamond cost a little less than a natural one. Today it costs much less. Indeed, much less. According to industry experts, a medium quality diamond grown in a laboratory now costs 40% less than a natural one. Two years ago the discount was only 18%. In addition, De Beers is also about to offer mass-produced lab-grown diamonds, almost as if they were Swarovski crystals, with a nearly 90% discount compared to natural diamonds.

People appreciates

Let’s go back to the original question? Would you like to have a diamond ring and pay half the price? A 2018 Consumer Research survey conducted by MVI Marketing found that most respondents would choose a larger lab-developed diamond over a smaller natural stone, for the same price. But those who want to buy a jewel that maintains or increases its value over time tend to prefer natural diamonds, which are more easily resalable.

Are they really ecological?

According to the manufacturers, one of the reasons driving the growth of artificial diamonds lies in their sustainability, that is, respect for the environment. But is it really so? It depends. Of course, compared to diamonds extracted in a primitive way, in mines that exploit local populations and that devastate the territory, or perhaps that are used to support wars, the impact of laboratories that produce synthetic diamonds is less. However, it must be added that where the mines are controlled and the mining activity is more modern, the work remains hard, but also necessary for the local populations. Countries such as Botswana, which were among the poorest in the world, today have greatly improved the average living conditions of the population thanks to the mining of precious stones. In addition, a lot of energy needs to be used to produce laboratory diamonds and, for example, in China most of the electricity originates in coal-fired power plants.

Anelli in oro bianco e oro giallo con diamanti di laboratorio by Pandora

According to industry experts, the most efficient diamond factories with the HPHT method today use around 700 kWh per carat, while CVD production uses even more, 1,000 kWh per carat of diamond produced. One study estimated that laboratory diamonds produce around 511 kilograms of carbon emissions. According to the mining companies, to extract a natural diamond, between fuel consumption and electricity, you get to just 160 kilograms of emissions. In short, according to the data of the companies that extract diamonds (and which must therefore be considered biased), extracting a natural stone pollutes less than producing it artificially. It is difficult to say how reliable these data are, but we must take note of what they say. In short, there are two sides to the coin.

Anello in oro bianco con diamanti lab grown

The Chrysler Diamond sold for 5 million by Christie’s

Published on June 9, 2021

news/Diamanti

Diamonds are the protagonists of Christie’s Magnificent Jewels auction in New York. The top-lot was, as expected, The Chrysler Diamond. It is a large pear cut diamond of 54.03 carats, color D, Internally Flawless. The stone sold for over $ 5 million. The history of this stone has contributed to its charm: in 1958 it was bought by Harry Winston. At that time the diamond was known as Louis XIV and from the estate of Thelma Chrysler Foy, daughter of Walter Chrysler, founder of the automotive group and of the iconic Art Deco skyscraper in New York City.

The Chrysler Diamond, diamante a forma di pera di 54,03 carati, colore D, Internally Flawless

Another protagonist of the auction was The Dancing Sun, a maxi intense yellow diamond of 204.36 carats, VVS2 clarity. It is the largest diamond of this type mined in North America. The stone was sold for 4.950 million. This stone, weighing 552.74 carats, was discovered in 2018 by the Diavik Diamond Mine in Canada.

The Dancing Sun, 204,36 carati, e altri diamanti gialli originari della stessa pietra grezza

The final balance of Christie’s auction reached a total of 26.5 million, which is 118% above the low estimate. 94% of the pieces were sold by value and 87% sold by lot. Among the attractions of the sale was a selection of 19 Jar jewels, owned by an important collection. The collection totaled 5.9 million, with many lots that far exceeded initial estimates. The selection was led by the Branch under Snow diamond bangle, exhibited at the Metropolitan Museum of Art in 2013-14 and sold for 1.89 million against its low estimate of 400,000.

Bracciale Branch under Snow di Jar, con diamanti

Additional highlights include The Flawless Match, a superb colored diamond and diamond ring comprised of a 2.52-carat fancy vivid blue pear-shaped diamond and a 2.43-carat pear-shaped diamond, color D, Internally Flawless , type IIa which reached 2.91 million. A 2.58-carat fancy deep purplish pink diamond sold for $ 675,000, against the lowest estimate of $ 200,000. A rare 4.10-carat blue-gray diamond ring achieved more than three times its sales estimate, at 846,000 and finally an 11.93-carat emerald-cut diamond, G color, VS2 clarity, by Harry Winston is was sold for $ 425,000.

The Flawless Match, anello composto da un diamante blu brillante a forma di pera di 2,52 carati e un diamante a forma di pera di 2,43 carati, colore D, Internally Flawless, Tipo IIa

anello di diamanti grigio-blu di 4,10 carati — Anello di diamanti grigio-blu di 4,10 carati

Bracciale di Jar in oro con diamanti bianchi e fancy

50 shades of gray diamond

Published on June 9, 2021

Campus/Diamanti

Moussaieff, anello con diamante grigio taglio smeraldo di 11 carati

What you need to know about the gray diamonds and the colorful shades they may have ♦

White diamonds are a classic. Colored ones are in fashion. But gray diamonds are in trend. There is only one problem: gray diamonds are rare, very rare. But they are considered very chic, also because they are perfect to combine with other colors: gray is a shade that manages to coexist with all the others, as well as alone. A gray diamond, in fact, is suitable to be combined with any dress and can be worn at any time of day.

Collana di Monique Péan con diamanti grigi chiari

Features. Gray diamonds are extracted in India, Russia, South Africa and Australia. The gray color comes from a high concentration of hydrogen or boron. But not only: gray diamonds often have different shades, due to a slight influence by other mineral elements.

De Beers, anello con diamante grigio taglio marquise

Colors. According to the Gia (Gemological Institute of America), there are many types of gray diamonds, even with extra coloring. There are Gray Purple, Gray-Blue, Gray-Green and so on. In addition, gray diamonds are also cataloged for color intensity: Light Gray, Fancy Light Gray, Fancy Gray, Fancy Dark Gray and Fancy Deep Gray. The most common shades according to Gia are yellow, green, blue and purple. The human eye, on the other hand, can distinguish about 500 shades of gray.

Diamante grigio tendente all'azzurro — Diamante grigio tendente all’azzurro

The cost. The price of diamonds is determined by the color, but also by the clarity and of course the size. In general, gray diamonds cost a little less than bright-colored ones, such as yellow or pink. And they cost less, on average, than colorless ones. Federico Graglia

Anello Amulet, oro rosa, diamante grigio — Rachel Boston, anello Amulet, oro rosa, diamante grigio

Anello con la figura dell'occhio in oro rosa e diamanti neri e grigi — Bee Goddess, anello con la figura dell’occhio in oro rosa e diamanti neri e grigi

Anello con diamanti grigi e opale — Suciyan, anello con diamanti grigi e opale

Anello Neraviglia, linea Gioia. Zaffiri neri e diamanti grigi — Al Coro, anello Neraviglia, linea Gioia. Zaffiri neri e diamanti grigi

Anello della collezione Just Rebel Star, in oro nero e diamanti neri e grigi

Spilla con diamante grigio-azzurro venduta da Christie’s

Anello con diamante grigio taglio marquise

Maurizio Pintaldi, anello con diamanti grigi e neri

How to recognize a diamond true or false

Published on May 22, 2021

Campus/Diamanti

Are you sure that the diamond on your ring is genuine? Here are 5 tricks to find out if (probably) your diamond is genuine ♦

A classic case: you want to know if the diamond on your grandmother’s engagement ring, which you inherited, is true or false. Or you are curious to know the truth about the diamond that they just gave you (on a beautiful ring), but about which you have doubts: what if it were an imitation? Or, finally, you just want to get rid of a brilliant ring that you have hardly ever worn, because you need to make some money. Yeah, but will that diamond really be real?

Let’s face it right away: to find out with absolute certainty you must contact a gemologist or a gemmology laboratory. Only a qualified professional can give you the guarantee that your diamond is authentic. Of course, if you also have a certificate of guarantee on the stone together with the diamond ring, you don’t need anything else.

But, if you are in a hurry, you can immediately get an idea of the authenticity of your diamond with a few simple tests at home. We repeat: they are not 100 percent safe tests, of course, but they can suggest valid indications to find out if you are holding a piece of glass or plastic instead of an authentic diamond. We might as well try, right? The result may surprise you.

One final caveat: these tests will not tell you if the diamond is natural or lab created. Synthetic diamonds, which are increasingly popular, in fact, have a chemical composition that is completely identical to natural ones. To distinguish artificially created diamonds, very expensive equipment and accurate laboratory tests are required. In any case, synthetic diamonds have only been on the market massively for a few years, so it’s not that likely that you have one. A home test, however, could indicate whether your diamond is actually a glass crystal.

Test number 1: magnifying glass

Bring a large magnifying glass or a pair of glasses with thick enough glasses. Or failing that, your child’s toy microscope. Look carefully at the inside of the stone. A real diamond very easily has very small inclusions, tiny imperfections that are micro traces of carbon or other minerals that have remained imprisoned in the gem. In this case, it’s a good clue: the diamond should be real. The fake gems, in fact, do not have any inclusion. Of course, if the diamond is of the highest quality it should still be free of imperfections, but in this case it will certainly have been paid a lot and should have a certificate that, for example, indicates purity. Any inclusions, and more generally imperfections, are therefore a good sign of the authenticity of a diamond.

Test number 2: breath test

Gently blow on the diamond, as you do to mist the lens of your glasses before cleaning them. Diamonds cannot retain heat: the water vapor on a real stone is immediately dispersed. On a (synthetic) zircon, however, it lasts longer. This system also works with synthetic stones called moissanite. Of course, it also depends on the surface of the diamond: it must be sufficient to allow observation. The greatest difficulty with this rudimentary method, however, is that you need to have another diamond available in order to make the comparison.

Un anello format Harry Winston e disegnato per Lisa Christiansen. Un grande diamante con zaffiri e Moissanite — Un anello Harry Winston e disegnato per Lisa Christiansen. Un grande diamante con zaffiri e Moissanite

Test number 3: under glass

If the diamond is mounted on a ring and protrudes a little, for example a solitaire, you can try using it to scratch a glass. You have to pass an edge of the stone on the surface of the glass and observe if it leaves a thin line engraved. Attention, however: even if diamond is the most resistant material, it does not mean that it cannot chip: to perform this test you must be very careful. In any case, if the stone does not leave even a scratch on the glass, it is more likely to be fake. However, there are some synthetic diamonds that can scratch the glass.

Test number 4: read the newspaper

If your diamond is of a suitable size (i.e. it is not microscopic) and is not mounted on a piece of jewelry, try placing it on a printed sheet of paper. A real diamond refracts the light and therefore does not allow the letters to be seen through it. On the contrary, for example, a zircon (cubic zirconia, a synthetic stone) has the effect of a moderate lens: you will see the printed letters enlarged. The magnifying effect also occurs with crystals.

Test number 5: let him swim

If you can disassemble the diamond, try putting it in a glass full of water: it will go to the bottom immediately, because it has a higher density. On the contrary, a fake diamond most of the time tends to float, because it does not have the same specific weight as the real diamond. It is an easy but effective method. Good luck.

Laboratorio Garavelli, la scelta delle pietre