Gypsum Rock identification and geology

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• Rock Salt
• Chalk

Sources, scope & corrections

These authoritative resources support category-level nomenclature, terminology, identification methods, and safety. When a specimen-specific safety warning appears, the public-health source listed here directly supports that precaution. They are not line-by-line citations for every other property on this entry, and natural specimens vary.

Editorial owner

GeoMiner

Last updated

2026-02-10T20:33:30.208882+00:00

Review status

Published; not independently peer-reviewed

• Rocks — U.S. National Park Service. Authoritative overview of rock groups, the rock cycle, and geologic processes.
• Can you identify my rock or mineral? — U.S. Geological Survey. Identification limitations and routes to in-person professional verification.

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Common questions

What is Gypsum Rock?

Sedimentary rock composed primarily of gypsum CaSO₄·2H₂O . Commonly associated with other evaporite minerals.

How can you identify Gypsum Rock?

Compare several properties rather than relying on colour alone. This entry records rock type: Sedimentary Chemical/Evaporite; texture: Crystalline to massive; grain size: Fine to coarse; common minerals: Gypsum, Anhydrite, Calcite, Clay. Confirm an important identification with additional field tests or qualified laboratory work.

How does Gypsum Rock form?

Precipitates from evaporating seawater or saline lakes at lower salinities than halite.

Where is Gypsum Rock commonly found?

Worldwide; Paris Basin, Persian Gulf, western USA; found in evaporite sequences.

What is Gypsum Rock commonly confused with?

Gypsum Rock may be confused with Rock Salt, Anhydrite Rock, Chalk. Compare multiple diagnostic properties because colour and surface appearance can overlap.