Tremolite

Real mineral · uncommon · Ca₂Mg₅Si₈O₂₂(OH)₂

Calcium magnesium amphibole forming in metamorphosed dolomitic marbles. The rare purple hexagonite variety is coloured by manganese. Fibrous tremolite is a form of asbestos.

Identity

Formula

Ca₂Mg₅Si₈O₂₂(OH)₂

Chemical class

silicate

Mineral group

Actinolite, Hornblende, Richterite

Also known as

Hexagonite (purple variety), Grammatite

Crystallography

Crystal system

monoclinic

Habits

prismatic, bladed, fibrous, massive

Fracture

subconchoidal

Physical properties

Mohs hardness

5.5

Density

2.99 g/cm³

Luster

vitreous, silky

Colors

white, gray, pale green, pink, colorless

Streak

white

Transparency

transparent, translucent

Geology

Origins

metamorphic

Host rocks

marble, dolomite, serpentinite

Associated minerals

Calcite, Dolomite, Diopside, Talc

Geography

Switzerland, Italy, USA, Canada, Pakistan

Classification

Rarity

uncommon

Gem quality

No

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