Brucite

Magnesium hydroxide forming pearly, flexible plates in serpentine and marble.

Brucite specimen — Photo: Robert M. Lavinsky, CC BY-SA 3.0, via Wikimedia Commons

How to identify brucite

Pearly white to pale green plates.
Flexible but not elastic flakes.
Soft.

Often confused with

Talc
Talc is softer and feels greasy.
Compare side by side
Gypsum
Gypsum is softer and doesn't dissolve in acid.
Compare side by side

Where it's found

Pakistan
Quebec, Canada
Gabbs, Nevada

Uses

Fire retardants and magnesium source.

Rock tumbling

Not suitable for tumbling.

Did you know?

It's named after Archibald Bruce, an early American mineralogist.

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