Sodalite

Real mineral · uncommon · Na₈(Al₆Si₆O₂₄)Cl₂

A sodium aluminium silicate chloride found in silica-undersaturated igneous rocks such as syenites and phonolites. Its characteristic blue colour varies with iron content. Displays strong orange fluorescence under shortwave ultraviolet light.

Identity

Formula

Na₈(Al₆Si₆O₂₄)Cl₂

Chemical class

silicate

Mineral group

Hauyne, Lapis Lazuli

Also known as

Princess Blue (trade name)

Crystallography

Crystal system

cubic

Habits

massive, dodecahedral, granular

Fracture

conchoidal

Physical properties

Mohs hardness

5.5

Density

2.3 g/cm³

Luster

vitreous, waxy

Colors

blue, dark blue, gray-blue, white

Streak

white

Transparency

translucent, opaque

Geology

Origins

igneous

Host rocks

syenite, phonolite, trachyte

Associated minerals

Nepheline, Cancrinite, feldspar

Geography

Canada (Ontario), Brazil, Namibia, Russia, India

Classification

Rarity

uncommon

Gem quality

Yes

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