Lazulite is a mineral with a hardness of 6 out of 10 on the Mohs scale of mineral hardness [?]. These Monoclinicly structured gems are made of magnesium aluminum hydroxyphosphate, their full chemical compound being MgAl2(PO4)2(OH)2.
Lazulite is a compact, pleochroitic mineral which forms a series to scorzalite. It is dichroic, with a monoclinic crystal system.
It appears as pointed, pseudo-dipyramidal, bright blue crystals in microgranular masses. It is hard, medium heavy, fragile with indistinct prismatic cleavage. It is translucent, with vitreous luster. It is infusible, discolors and breaks into small fragments when heated. It dissolves with diffulty in strong hot acids.
It is a deep blue mineral, and has refractive indices in the range of tourmaline with a higher birefringence. Its pleochroism ranges strong from colorless to blue and deep blue.
Under LWUV (long wave ultraviolet) light it shows spots or streaks of an orange or copper-red. Pinkish under SWUV (short wave ultraviolet light). Yellowish glow under X-rays. Sometimes whitish fluorescence under SWUV.
Lazulite occurs in hypersilicic rocks, igneous (pegmatites, quartz veins), where it is associated with andalusite and rutile, or in metamorphic rocks (quartzites), where it occurs with quartz, corundum, kyanite, sillimanite, garnet, and sapphirine.
Beautiful crystals up to 2 inches long were found in the quartzites of Grave Mountain (Georgia, USA); at Zermatt (Switzerland), Werfen and Vorai (Austria); and Horrsjoberg (Sweden). Scorzalite, the iron analog of lazulite, is found mainly in pegmatites in Brazil.
Fine blue transparent lazulite may resemble Paraiba tourmaline, this material originating probably from west of Dattas, Minas Gerais, Brazil. Fine green material is also found in the Chilas area of the northern areas of Pakistan, and Angola is another possible source.
A variety of lazulite is called berkeyite - a blue, transparent gem quality variety of lazulite from Brazil.
Other names for lazulite include azure spar, blue spar, and klaprothine.
Misnomers for lazulite include blue opal, false lapis, and false lapis lazuli.
Lazulite is not to be confused with lazurite.
Lazulite derives its name from the Arabic word meaning "heaven," or the German "lazurstein" meaning "blue stone," in reference to its colour.It was first described in 1795 for deposits from Styria, Austria.
Lazulite is used as ornamental article and seldom cut as gemstone. It is an attractive ornamental stone of minor importance.