Epsomite
Image: Mai Seppel (CC BY-SA 4.0)
Mineral NameEpsomite
Chemical FormulaMgSO₄·7H₂O
Mohs Hardness2
Crystal Systemorthorhombic
Lustervitreous
Streak Colorwhite
Cleavageperfect on {010}
Fractureconchoidal
Specific Gravity1.67
Colorswhite, colorless, pinkish, greenish
Transparencytransparent
Type LocalityEpsom, Surrey, England
Mineral GroupSulfates
Usesmedicinal, agricultural, industrial
Associated Mineralsgypsum, mirabilite, halite, thenardite
Raritycommon
Description
Epsomite typically forms as white to colorless, delicate acicular or fibrous crystals, often appearing as crusts or efflorescences. The specimen shown is a mass of fine, white, fibrous crystals.
Geological Context
It forms primarily as an evaporite mineral in arid climates, often found as efflorescences on cave walls, mine workings, or in saline lake deposits. It precipitates from magnesium-rich sulfate solutions.
