How many carats is your diamond in? And how many karats is your gold ring instead? For those who are not a jewelry expert or do not know the basic rules of the world of jewelry, the carats are a big mess. The carats that are the unit of measurement needed for precious stones and pearls, in fact, are a completely different thing from the karats that refer to gold. Did you know? In English, everything is easier: the carats that measure diamonds start with the letter C while those for gold start with the K. In other languages, however, it is written the same way and everything is more complicated.
This is why we must be careful not to confuse the different concepts: the carats of diamonds (or rubies, emeralds, sapphires, etc.) with the karats that are related to gold. Here’s how to distinguish.
The carats of the stones
The carat (the abbreviation is ct) is a unit that indicates the mass of a stone or pearl. Carats are used for convenience, after in past each country regulated itself differently for centuries. For those who traded in diamonds or other stones it was therefore difficult to work. In Florence, for example, the basic unit of measurement was equivalent to 197.2 milligrams, while in London to 205.49. After much discussion, in the end, in 1907 it was decided to adopt 200 milligrams as a carat measure. A single carat, therefore, equals one fifth of 1 gram.
Now you know exactly how much the diamond on your finger weighs: divide the number of carats by five and you will have the weight in grams. Or, more easily, in milligrams, since it is not common to wear a diamond that weighs 5 carats (and therefore 1 gram). for this reason the carat is divisible into 100 points of 2 milligrams.
By the way, why is the carat called so? The origin seems to be linked to carob seeds. The word carat derives from the Arabic qīrāṭ قيراط, which however is derived from the Greek kerátion κεράτιον, which indicates carob seeds. And these seeds were used to weigh jewels, thanks to their always regular shape. Then the term carat was used in Italy and later in the rest of the world. The use of the carat unit of measurement to weigh diamonds dates back to 1570.
The karats of gold
The carats of diamonds, precious stones and pearls refer to weight. The karats of gold, on the other hand, indicate the percentage of yellow metal present in a jewel, its fineness. The term karat has prevailed among the many systems adopted in the past and, in particular, on the measurement of pounds and ounces, which are still used for the weight of gold, platinum or silver. So why this confusion? Simple: the ancient origin of the word is the same, i.e. the carats used to measure precious materials.
In the case of the karats that refer to gold, however, they indicate the thousandths of quantities of gold (or other precious metals) contained in an alloy. The maximum, as regards gold, is 24 karats. You will never find gold of 25 or more carats. The 24 karats indicate that the gold is 100% pure. The 24 karats are the basis for calculating the rest (always for gold). The 18-karat jewels, therefore, are 75% gold. It is calculated as follows: 18: 24 = 0.75. Similarly, a jewel with 14% gold means that it contains slightly more than half of gold, the rest are other metals (14: 24 = 0.58).
In some cases, the karats of gold can also be indicated with the number that refers to the percentage (the result of the arithmetic division). For example, 18-karat gold can also be indicated with the initials 750, 14-karat gold with 583 and so on. Again, if you read the number 375 in a jewel, know that it equals 9 karats.
The karats are also used for silver. The silver sterling, for example, contains 92.5% of silver and 7.5% of other metals, generally copper. It is generally referred to as 925 silver.
