Bohseite
Bohseite is an IMA-recognized mineral species in the silicate class, with the chemical formula Ca₄Be₃₊ₓAl₁₋ₓSi₉O₂₅₋ₓ(OH)₃₊ₓ (x = 0 to 1).
It crystallizes in the orthorhombic crystal system (space group Cmcm). It is a member of the Bavenite structural group.
Key properties: Mohs hardness 5–6; specific gravity 2.719; White streak; Vitreous luster; optically biaxial.
IMA symbol Bhs, IMA status: approved, named in 2010.
Found in strongly fractionated parts of zoned anatectic (NYF-LCT) pegmatite dikes that cut amphibolite.
It is found associated with Microcline, Cs-rich beryl, phenakite, helvite, lepidolite, bertrandite (Poland).
The mineral was named to honor the Danish geologist Hennning Bohse (b. 1942) who has worked for more than 40 years on the mineralogy and geology of the Ilímaussaq alkaline complex.