Aragonite
Image: Tomaž Planina (CC BY-SA 4.0)
Mineral NameAragonite
Chemical FormulaCaCO3
Mohs Hardness3.5
Crystal Systemorthorhombic
Lustervitreous
Streak Colorwhite
Cleavagedistinct on {010}, poor on {110} and {011}
Fracturesubconchoidal
Specific Gravity2.95
Colorswhite, colorless, yellow, pink, blue, green
Transparencytransparent
Type LocalityRavenska jama near Cerkno, Slovenia
Mineral GroupCarbonates
Usescollector, ornamental stone, jewelry (rarely)
Associated Mineralscalcite, dolomite, gypsum, limestone
Raritycommon
Description
The image shows several clusters of delicate, needle-like white aragonite crystals, forming radiating or 'flos ferri' habits, growing on a textured brown cave ceiling.
Geological Context
Aragonite is a polymorph of calcite and forms in various low-temperature environments, including sedimentary and metamorphic rocks, hydrothermal veins, and especially in caves where it precipitates from supersaturated waters, often forming delicate speleothems like 'cave flowers'.
