Khmaralite
A beryllium-bearing member of the sapphirine group associated with sillimanite, musgravite and garnet.
Intro adapted from Wikipedia (CC BY-SA).
Khmaralite is an IMA-recognized mineral species in the silicate class, with the chemical formula Mg₄(Mg₃Al₉)O₄[Si₅Be₂Al₅O₃₆].
It crystallizes in the monoclinic crystal system (space group P2_1/c). It is a member of the Sapphirine structural group.
Key properties: Mohs hardness 7; specific gravity 3.61; Green-gray streak; Vitreous luster; optically biaxial.
IMA symbol Kma, IMA status: approved, named in 1998.
Found in a pegmatite metamorphosed at granulite-facies likely from pre-existing pegmatitic Be phases such as beryllian cordierite.
It is found associated with Surinamite, musgravite, sillimanite, garnet, biotite, apatite, rutile, dumortierite, quartz, microcline.
The name is derived from the locality, from which the first samples were collected, named for Ivan Fedorovich Khmara (1936-1956).