Onyx is commercially classified as a sibling to marble because these two stones have the same mineral content. Onyx is made of calcite, which is the same mineral that makes up limestone, marble, and travertine. Onyx forms from spring water or groundwater that has an abundance of calcite dissolved in it.
Durability: if properly cared for and maintained, onyx can last upward of 100 years. Lighting: perhaps the most unique feature of onyx is its translucency, which means the stone can be backlit
Care and Maintenance: to retain their beauty, Onyx must be sealed upon installation and re-sealed at regular intervals, and should be polished occasionally. If there are spills, the stone should be cleaned immediately using a special formula cleaner.