Gypsum (Desert Rose)
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Mineral NameGypsum (Desert Rose)
Chemical FormulaCaSO₄·2H₂O
Mohs Hardness2
Crystal Systemmonoclinic
Lusterdull
Streak Colorwhite
Cleavageperfect on {010}
Fractureconchoidal to uneven
Specific Gravity2.32
Colorsbrown, tan, reddish-brown, white
Transparencytranslucent to opaque
Type LocalityWorldwide, particularly arid regions like the Sahara Desert, Oklahoma (USA), Mexico
Mineral Groupsulfates
Usesornamental stone, collector
Associated Mineralssand, clay, halite, anhydrite
Raritycommon
Description
A rosette-like aggregation of tabular gypsum crystals, often incorporating sand grains, giving it a sandy brown or tan color and a petal-like appearance.
Geological Context
Forms in arid, evaporitic environments such as playas and shallow saline lakes, where groundwater rich in dissolved sulfates evaporates, allowing gypsum crystals to grow within sand or clay.
