Scientific Name: Calcium carbonate
Chemical composition: CaCO3
Colors: sky blue
Hardness: 3.5 to 4
Formation: Elongated prismatic crystals.
Principal Sources: Czech Republic, Mexico, Austria, Greece, Morocco, England, France, Germany, Italy, Hungary, Japan, USA
Special Notes: Forms in metamorphic and sedimentary rocks, often near hot springs. Crystals often twin creating "Flos Ferri" or "flowers of iron." Argentinian aragonite is a deep tangerine orange with white frothy inclusions.