Onyx is a type of chalcedony, or quartz with a different structure. Its colors are black, black and white, and grey and white. It is not particularly rare nor expensive. In ancient times, it was much more precious than it is now.
The most well known type of onyx is black onyx – the type most often found in jewelry. However, onyx also comes in banded grey colors and sometimes in patterns.
The best onyx is also slightly transparent – it has a kind of subtle glow that you notice after looking at a lot of different quality levels.
Onyx is very commonly dyed to give it a “blacker” and more even color. Onyx, like all chalcedony, is porous and absorbs color quite easily. It can be difficult to distinguish onyx gemstones that have been dyed from natural gemstones, but that’s okay because dyeing is considered very normal in the industry.
Sometimes we see stones on the market with names like “green onyx” or “red onyx.” If these are natural stones, then they are probably just other varieties of chalcedony: onyx only comes in shades of grey, black and white.
|This is a strand of black onyx beads – they are nicely cut and polished – very typical of the gem. Beads like this are easy to find and inexpensive.|
|These onyx earrings make excellent use of what black onyx has to offer – the material is so inexpensive that a designer can afford to cut away a lot of stone for the sake of a cool design – these earrings were each cut from one solid stone.|