Onyx is, simply put, mesmerizing. Onyx is a calcareous stone, formed by dissolving limestone and redeposited as a new kind of stone. In caves, drip water forms onyx as stalactites and stalagmites. It is a beautiful but brittle stone and should be carefully evaluated for its intended use. Being a calcium-based stone, Onyx is susceptible to acid and etching so using a non-acidic cleaner is necessary.  Onyx ranks about a 6.5 on the Mohs Hardness Scale. Its deep, rich tones suggest comfort and strength while its layering tells a story of the earth’s growth and its veins add an aura of life and vitality to any space.