Spessartine

Real mineral · uncommon · Mn₃Al₂(SiO₄)₃

Manganese aluminium garnet ranging from orange to red-brown in colour. Forms in granites, pegmatites, and metamorphic rocks rich in manganese. The bright orange mandarin variety from Nigeria is particularly prized.

Identity

Formula

Mn₃Al₂(SiO₄)₃

Chemical class

silicate

Mineral group

Demantoid, Garnet, Grossular, Tsavorite, Uvarovite

Also known as

Spessartite, Mandarin garnet (orange variety)

Crystallography

Crystal system

cubic

Habits

dodecahedral, massive

Fracture

conchoidal

Physical properties

Mohs hardness

7.5

Density

4.18 g/cm³

Luster

vitreous

Colors

orange, red, yellow, orange-red

Streak

white

Transparency

transparent, translucent

Geology

Origins

metamorphic, igneous

Host rocks

granite, pegmatite, schist

Associated minerals

Quartz, Mica, Tourmaline

Geography

Nigeria, Brazil, USA, Germany, Tanzania

Classification

Rarity

uncommon

Gem quality

Yes

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