Onyx

Onyx is an ancient gemstone, having been used in jewelry and as an ornamental gemstone for carvings since antiquity. Onyx has traditionally been one of the most important engraving and cameo gemstones, where its most common form was a black base with a white upper layer. Although still used a minor gemstone today, the significance and value of Onyx has been diminished as compared to ancient times. 

In the trade there are major two colors are available i.e; Black, White.

Whereas Green and Red  are pretty popular colors nowdays