Aragonite (calcium carbonate) is formed under low-temperature and surface conditions, it is a late mineral of hydrothermal deposits and epithermal veins, and is abundant on thermal springs and geysers. It is formed by decomposition of calcium basalt and its lava by autohydration. It is present in sediments or is present as a component of stalactites. They form short or long prismatic crystals, columnar or filamentous crystals, they are stellar, pizolitic (pea) or whitebry (aggregate) aggregates. Twin adhesions are known, and the intergression of three crystals is rarely known, resulting in a pseudohexagonal appearance. Colors are white, gray, yellow-white, greenish, reddish, yellow-white, bluish, violet, also colorless. It is transparent to translucent, pleochroism is unknown, it is thermoluminescent. White or colorless scratch. Glass gloss on crystal surfaces, pitch on quarry surfaces.