Cancrinite

Real mineral · uncommon · Na₆Ca₂Al₆Si₆O₂₄(CO₃)₂

A feldspathoid carrying carbonate in its framework, formed where alkaline magma met limestone or its own late fluids. Its yellow to orange masses effervesce weakly in acid, unusually for a silicate.

Identity

Formula

Na₆Ca₂Al₆Si₆O₂₄(CO₃)₂

Chemical class

silicate

Crystallography

Crystal system

hexagonal

Habits

prismatic, massive, granular

Fracture

conchoidal

Physical properties

Mohs hardness

6

Density

2.45 g/cm³

Luster

vitreous

Colors

blue, colorless, gray green, yellow, white

Streak

white

Transparency

transparent, translucent

Geology

Origins

igneous, hydrothermal

Host rocks

syenite, pegmatite

Associated minerals

Nepheline, Sodalite, Aegirine, Calcite

Geography

Russia, Canada, Norway

Classification

Rarity

uncommon

Gem quality

No

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