Onyx is a silicate class mineral, a chalcedony type of quartz with minor impurities of other substances. The inclusions create plane-parallel layers of various colors. Layering is a key decorative property of the material, due to which onyx is actively used for the manufacture of small and medium plastics.
Marble onyx belongs to sedimentary rocks. The stone is formed during the layering of carbonate minerals in hot springs. With the rapid growth of crystals, travertine (calcareous tuff) is formed, but when the crystallization process slows down, calcite forms large crystals with patterned lamination. The rock is colored with additional inclusions of magnesium, iron, iron oxides, copper. Aragonite is often found in marble onyx - a white mineral with less transparency.