What is the difference between onyx stone and black opal?

 What is the difference between onyx stone and black opal?

The difference between black agate and onyxbar Contrary to popular belief, onyx stone is not black agate, and of course, in the stone market, names such as Jaza Yamani, Soleimani agate strip, etc. have become popular, which are not scientific names. Black agate is usually a very dark brown type and completely black color is less seen in it. In fact, black agate and onyx are both types of chalcedony layers (a type of microcrystalline quartz) that differ in the type of strips and bands on the stone.

Agate has centrifugal rotating bands like rings, while onyx has parallel and straight bands. Onyx strips are usually black or white, but can be a collection of colors with shades of blue to purple. Often these bands start in the light and separate in the dark. In opal, the layers between the bands can have different colors. There is also a little bit of transparency in the agate and the stone can have different colors. But in Onyx, the colors are generally matte and uniform (about one or two colors). Onyx is usually opaque to OPEC.