IMA mineral species

Sapphirine

Mg₄(Mg₃Al₉)O₄[Si₃Al₉O₃₆]

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.

Red Yellow Green Blue Gray White & Clear

Sapphirine specimen — Sapphirine (Madagascar).jpg · Wikimedia Commons (see file page for author & license)

Properties

⛏ Mohs hardness7.5

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💅🪙🍶🔪💎

Harder than quartz: scratches glass and steel.

🔷 Monoclinic✏️ streak white

Chemical formula	Mg₄(Mg₃Al₉)O₄[Si₃Al₉O₃₆]
Elements	Mg, Al, O, Si
Crystal system	Monoclinic
Mohs hardness	7.5
Density	—
Streak	white
Color	—
IMA symbol	Spr
Nickel–Strunz class	9.DH.45

“—” means no reliable value in Wikidata yet. Check Mindat for full data.

Learn more

Sapphirine on Mindat.org
Wikipedia article
Wikidata item Q419794 (source of this page's data – you can correct it there)