lazurite

{{Infobox mineral | name = Lazurite | category = Tectosilicate minerals | group = Feldspathoid group, sodalite group | boxwidth = | boxbgcolor = #2e337f | boxtextcolor = #FFFFFF | image = Lazurite.jpg | imagesize = | caption = Lazurite, Ladjuar Medam (Lajur Madan; Lapis-lazuli Mine), Sar-e-Sang District, Koksha Valley (Kokscha; Kokcha), Badakhshan (Badakshan; Badahsan) Province, Afghanistan | formula = | IMAsymbol = Lzr | strunz = 9.FB.10 | system = Isometric | class = Hextetrahedral (3m) H-M symbol: ( 3m) | symmetry = P3n | unit cell = a = 9.09 Å; Z = 2 | color = Deep blue, azure, violet-blue, greenish blue | habit = Crystals occur as dodecahedra, or rarely cubes; granular, disseminated, or massive | twinning = | cleavage = Imperfect on {110} | fracture = Uneven | tenacity = Brittle | mohs = 5–5.5 | luster = Vitreous | refractive = 1.502–1.522 | opticalprop = Isotropic; anomalously anisotropic | birefringence = | pleochroism = | streak = | gravity = 2.38–2.45 | density = | melt = | fusibility = 3.5 | diagnostic = | solubility = Soluble in HCl | diaphaneity = Translucent to opaque | other = | references = }}

Lazurite, old name Azure spar is a tectosilicate mineral with sulfate, sulfur and chloride with formula . It is a feldspathoid and a member of the sodalite group. Lazurite crystallizes in the isometric system although well‐formed crystals are rare. It is usually massive and forms the bulk of the gemstone lapis lazuli.