Onyx mat
MAT onyx
The name "Onyx" is taken from a legend: one day, while Venus was sleeping, Cupid cut his nails and left the clippings scattered on the ground. The Parques picked them up and transformed them into a gemstones.
Onyx is a stone that appears in various cultures and is considered one of the most popular gemstones in the world.
It is a type of oxide mineral that has dominant silica ingredients. The stone itself is famous for its silky and beautiful luster which also looks glassy if the stone is already treated and polished. The black onyx is of course the best known and most sought after variant.
Onyx is a banded gem (variety of agate whose bands are circular and concentric) with a combination of black and white layers. Except for the size of the cameos, we use the black part of the onyx for stones in jewelry. It is opaque and black to dark brown in color. Onyx is mainly found in Brazil, India, Madagascar and even Uruguay. But other smaller deposits have been discovered. It is a stone that is quite rare in nature. 
Learn more about onyx: Wikipedia