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Lazulite
Chemical Formula	(Mg,Fe2+)Al2(PO4)2(OH)2
Species	Phosphates
Crystal System	Monoclinic
Mohs Scale	5-6
Specific Gravity	3.122-3.240
Color	Azure-blue, sky-blue, bluish white, yellow-green, blue-green, rarely green
Streak	White
Luster	Vitreous
Refractive Index	n = 1.604 - 1.626 n = 1.626 - 1.654 n = 1.637 - 1.663
Diaphaneity	Transparent, Translucent
Cleavage	Poor/IndistinctPoor to good Indistinct on
Fracture	Irregular/Uneven, Splintery
Crystal Habit：Tabular, acute to stubby bipyramidal crystals; granular, massive
Geological Setting：In metamorphic rocks, border zones of complex granitic pegmatites, alluvial deposits.

Lazulite ((Mg,Fe²⁺)Al₂(PO₄)₂(OH)₂) is a blue, phosphate mineral containing magnesium, iron, and aluminium phosphate. Lazulite forms one endmember of a solid solution series with the darker iron rich scorzalite.

Lazulite crystallizes in the monoclinic system. Crystal habits include steep bipyramidal or wedge-shaped crystals. Lazulite has a Mohs hardness of 5.5 to 6 and a specific gravity of 3.0 to 3.1. It is infusible and insoluble.

Occurrence and discovery

It forms by high grade metamorphism of high silica quartz rich rocks and in pegmatites. It occurs in association with quartz, andalusite, rutile, kyanite, corundum, muscovite, pyrophyllite, dumortierite, wagnerite, svanbergite and berlinite in metamorphic terrains; and with albite, quartz, muscovite, tourmaline and beryl in pegmatites. It may be confused with lazurite, lapis lazuli or azurite.

It is found in Salzburg, Austria; Zermatt, Switzerland; Minas Gerais, Brazil; Lincoln County, Georgia; Inyo County, California; the Yukon in Canada, and elsewhere.

It was first described in 1795 for deposits in Styria, Austria. Its name comes from the German lazurstein, for blue stone or from the Arabic for heaven.