Lazulith (blauschwarze Kristalle) mit Quarz (farblos = Bergkristall) Fundort: Rapid Creek, Yukon, Kanada Kamera und Fototechnik: Erstellt mit Olympus OM-1 und d — Photo: HolDu · CC BY-SA 3.0 de
Lazulite
Also known as: Blue spar.
A blue magnesium-iron-aluminium phosphate — 'azure spar' — forming a series with the darker scorzalite.
Intro adapted from Wikipedia (CC BY-SA).
Lazulite is an IMA-recognized mineral species in the phosphate class, with the chemical formula MgAl₂(PO₄)₂(OH)₂.
It crystallizes in the monoclinic crystal system (space group P2_1/c). It is a member of the Lazulite structural group.
Key properties: Mohs hardness 5.5–6; specific gravity 3.12–3.24; typically blue; White streak; Vitreous luster; refractive index 1.635; optically biaxial.
IMA symbol Lzl, IMA status: approved, named in 1795.
Disseminated in metamorphic quartzites, schists and quartz veins; in the border zones of complex granite pegmatites; in alluvium and colluvium.
It is found associated with Quartz, andalusite, rutile, kyanite, corundum, muscovite, pyrophyllite, dumortierite, wagnerite, svanbergite, berlinite (metamorphic); albite, quartz.
The name comes from the German lazurstein, for blue stone.
Collections: Collector Favorites, Gemstones.