Gypsum with Sulfur
Image: <a href="//commons.wikimedia.org/wiki/User:Archaeodontosaurus" title="User:Archaeodontosaurus">Didier Descouens</a> (CC BY-SA 4.0)
Mineral NameGypsum with Sulfur
Chemical FormulaCaSO₄·2H₂O
Mohs Hardness2
Crystal Systemmonoclinic
Lustervitreous
Streak Colorwhite
Cleavageperfect in one direction
Fractureconchoidal
Specific Gravity2.31
Colorswhite, colorless, yellow
Transparencytransparent to translucent
Type LocalityCianciana, Agrigento Province, Sicily, Italy
Mineral GroupSulfates
Usesindustrial, collector, fertilizer, construction
Associated Mineralssulfur, calcite, anhydrite
Rarityuncommon
Description
A specimen featuring large, tabular to bladed, transparent to translucent white gypsum crystals, partially covered and intergrown with bright yellow, granular masses of elemental sulfur.
Geological Context
This specimen formed in an evaporitic environment, where gypsum precipitated from saline waters. The associated elemental sulfur likely formed through the bacterial reduction of sulfate minerals like gypsum or anhydrite, often in the presence of hydrocarbons, a common occurrence in the Sicilian sulfur deposits.
