Photo: Géry Parent · Copyrighted free use

A rare mineral of the sapphirine supergroup, single chain inosilicate mineral with polytopes 1A, 2M, 3A, 4M, 5A; a silicate of magnesium and aluminium, (Mg,Al)₈(Al,Si)₆O₂₀ (with Fe as a major impurity); named after its sapphire-like colour

Properties

Chemical formula

Mg₄(Mg₃Al₉)O₄[Si₃Al₉O₃₆]

Group

Silicates

Crystal system

Monoclinic

Hardness (Mohs)

—

Color

Blue

Luster

—

Streak

White

Density

—

Cleavage

—

Fracture

—

Tenacity

—

Crystal habit

—

Transparency

—

Space group

—

Fluorescence

—

Magnetism

—

Radioactivity

—

Refractive index

—

Optical character

—

Birefringence

—

Pleochroism

—

Strunz classification

9.DH.45

Dana classification

—

IMA status

Grandfathered mineral (G)

IMA symbol

Spr

Locality

—

Type locality

—

Discovery year

—

Source: Wikidata