Maleevite
Maleevite is an IMA-recognized mineral species in the silicate class, with the chemical formula BaB₂Si₂O₈.
It crystallizes in the orthorhombic crystal system (space group Pnma). It is a member of the Danburite structural group.
Key properties: Mohs hardness 7; specific gravity 3.78; White streak; Vitreous, slightly greasy. Bright blue fluorescence in short-wave UV luster; optically biaxial.
IMA symbol Mle, IMA status: approved, named in 2002.
Found in a slightly rounded block of pegmatite in syenite within a boulder in the moraine of the Dara-i-Pioz glacier, Alai mountain range, Tien Shan, northern Tajikistan.
It is found associated with Quartz, microcline, aegirine, with subordinate arfvedsonite, polylithionite, reedmergnerite, cesium-kupletskite, hyalotekite, albite.
The mineral was named to honor Bulgarian mineralogist Mikhael Naidenovich Maleev (b. 1940).