Aragonite
Image: <a href="//commons.wikimedia.org/wiki/User:Iifar" title="User:Iifar">Ivar Leidus</a> (CC BY-SA 4.0)
Mineral NameAragonite
Chemical FormulaCaCO₃
Mohs Hardness3.5
Crystal Systemorthorhombic
Lustervitreous
Streak Colorwhite
Cleavagedistinct on {010}, imperfect on {110} and {011}
Fracturesubconchoidal
Specific Gravity2.95
Colorsyellowish-orange, honey, white, colorless, gray, green, blue, violet, brown, pink
Transparencytranslucent
Type LocalityPantoja, Toledo, Castile-La Mancha, Spain
Mineral GroupCarbonates
Usescollector, industrial, minor jewelry
Associated Mineralscalcite, gypsum, celestine, malachite, azurite
Raritycommon
Description
This specimen displays a radiating cluster of translucent, yellowish-orange, needle-like aragonite crystals forming a spiky, star-like aggregate.
Geological Context
Aragonite is a polymorph of calcite that forms in low-temperature environments such as sedimentary rocks, hot springs, caves, and in the shells of marine organisms. It is metastable and can transform into calcite over geological time.
