Epsomite

MgSO₄·7H₂O

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.

Epsomite Physical Properties

Mohs Hardness

Crystal System

orthorhombic

Luster

vitreous

Streak Color

white

Cleavage

perfect on {010}

Fracture

conchoidal

Specific Gravity

1.67

Colors

white, colorless, pinkish, greenish

Transparency

transparent

Type Locality

Epsom, Surrey, England

Mineral Group

Sulfates

Uses

medicinal, agricultural, industrial

Associated Minerals

gypsum, mirabilite, halite, thenardite

Rarity

common

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.

Back to Collection

Related Specimens

Ilmenite

Turquoise

Ruby

Elbaite

Vivianite

Chlorite