Gypsum

An important construction material that has been used for thousands of years

 Selenite

 Alabaster

 Satin Spar

What is Gypsum?

Gypsum is an evaporite mineral most commonly found in layered sedimentary deposits in association withhalite, anhydrite, sulfur, calcite, and dolomite. Gypsum (CaSO₄^.2H₂O) is very similar to Anhydrite (CaSO₄). The chemical difference is that gypsum contains two waters and anhydrite is without water. Gypsum is the most common sulfate mineral.

Uses of Gypsum

Gypsum uses include: manufacture of wallboard, cement, plaster of Paris, soil conditioning, a hardening retarder in portland cement. Varieties of gypsum known as “satin spar” and “alabaster” are used for a variety of ornamental purposes; however, their low hardnesslimits their durability.