Albite

Real mineral · common · NaAlSi₃O₈

The sodium end of the plagioclase feldspar series, and one of the commonest minerals of the crust. Its repeated twinning rules the fine striations seen on cleavage faces of granites and pegmatites.

Identity

Formula

NaAlSi₃O₈

Chemical class

silicate

Mineral group

Labradorite, Moonstone, Sunstone

Also known as

Sodium feldspar, Peristerite

Crystallography

Crystal system

triclinic

Habits

tabular, prismatic, massive

Fracture

uneven

Physical properties

Mohs hardness

6.5

Density

2.62 g/cm³

Luster

vitreous

Colors

white, gray, greenish gray, bluish green, gray

Streak

white

Transparency

transparent, translucent

Geology

Origins

igneous, metamorphic

Host rocks

granite, pegmatite, gneiss

Associated minerals

Quartz, Mica, Tourmaline, Beryl

Geography

Sweden, Brazil, USA

Classification

Rarity

common

Gem quality

No

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