Aragonite formed from precipitating water that traps in organic matter, such as leaves, twigs, and moss. Also calcareous mounds formed from deposition of hot springs that trap in organic matter. Aragonite can occur in many different colors ranging from Colorless, white, brown, gray, yellow, reddish, pink, purple, light blue, to light green. It has a hardness of 3½ - 4. Its composition consists of, Calcium carbonate, sometimes with some strontium, lead, and zinc. Its Chemical formula is: CaCO3 The most common crystallized form of Aragonite that we deal in is in ball-like protrusions of pseudohexagonal crystals.