What is a black opal? How much is it worth? And why is it often considered more valuable than other opals? Here’s what you need to know about the black opal ♦ ︎
Think about it: jewels with a black opal in the center are more and more appreciated. Not only: on average they cost more than others. The opal is a stone that came back into fashion a few years ago and black opal is the queen of this type of gem.
The opal is a stone famous for its iridescent shades. In geology it is considered a mineraloid, and is chemically an amorphous hydrated form of silica. It is also the national gemstone of Australia, the countries where black opals are found. And, in particular, in the area of Lightning Ridge, the capital of opals.
We must also add that there are two large classes of opal: the precious ones and the common ones. The precious opal has its famous iridescence, while the common opal does not. The iridescence is caused by the internal structure of the opal, which causes the diffraction of light, with the consequent change in color. The black opal is considered the rarest, while white, gray and green are the most common.
Why is the black opal so rare? The tough activity to extraction ranks among the most frustrating activities in the world. To find a black opal you have to dig holes at random in particularly rich areas, where the diggers fit into an extremely deep well, risking to fall for about twenty meters, they risk their lives. In short, when you see a jewel with black opal, know that finding it has cost effort and risk. Of course, the prospect of a profit corresponds to work: a large black opal can reach up to 15,000 Australian dollars (about 9200 euros).
What distinguishes black opals? Black opals have traces of carbon and iron oxide. The body of the gem varies from black to dark gray. In short, the black opal is not black: it is colored on a dark background. It is this unusually dark shade that allows rainbow iridescences to appear more vividly than light opals. Of course, not all black opals are the same: the value of stone may depend on many other factors, such as brightness, body color, shape, colors, and any defects.
How are opals cut? Usually, the classic cut of opal is the cabochon. The way an opal has been polished and cut has a great influence on the overall value. The cut affects its final price.
For those who believe … There are many people who imagine that stones have special powers and can affect the lives of men. In the Middle Ages, the opal was considered a lucky stone. Some thought it could guarantee invisibility if the opal was wrapped in a fresh, hand-held bay leaf, much like the Harry Potter cloak. But in the nineteenth century, the opal became suddenly suspect. In a novel by Walter Scott a woman wears an opal with supernatural powers: when a drop of holy water falls on the stone, it becomes colorless and the woman dies shortly after. After the novel, the opal was referred to as porta bad luck and sales in Europe fell by 50%. Who was right?