Siderite
Image: Didier Descouens (CC BY-SA 3.0)
Mineral NameSiderite
Chemical FormulaFeCO3
Mohs Hardness3.5
Crystal Systemtrigonal
Lustervitreous
Streak ColorWhite
CleavagePerfect rhombohedral {1011}
FractureUneven to conchoidal
Specific Gravity3.96
Colorsbrown, yellowish-brown, reddish-brown, amber
TransparencyTransparent
Type LocalityMorro Velho mine, Nova Lima, Minas Gerais, Southeast Region, Brazil
Mineral GroupCarbonates
Usesminor iron ore, collector's specimens, gemstone
Associated Mineralspyrite, chalcopyrite, galena, sphalerite, quartz, fluorite, barite
Rarityuncommon
Description
This image displays a faceted, rectangular-cut siderite gemstone, exhibiting a warm brownish-orange to amber color with excellent transparency and internal brilliance.
Geological Context
Siderite typically forms in hydrothermal veins, sedimentary ironstone deposits, and as a gangue mineral in ore deposits, often associated with other sulfides.
