Rossmanite

General Information: Chemical Formula:[ ]LiAl2Al6(Si6O18)(BO3)3(OH)4 Composition:(Molecular Weight = 938.28 gm)Lithium 0.74 % LiAluminum 5.75 % AlSilicon 17.96 % SiBoron 6.91 % B Hydrogen 0.43 % H Oxygen 68.21 % O  Empirical Formula: LiAl2Si6O18(BO3)3(OH)4 Environment:Granitic pegmatite hosted by biotite and hornblende gniess. IMA Status:Approved IMA (Dana # Added) Locality:Found in the Hradisko quarry, in the Rozn  lepidolite subtype of granitic pegmatite, northeastern part of the Str zek Moldanubicum, Czech Republic. Name Origin:Named after George R. Rossman (1945-), California Institute of Technology, Pasadena, CA, USA, in recognition for his work on the spectroscopy of the tourmaline minerals.Physical Properties: Cleavage:None Color:pink or pale pink. Density:3 Diaphaniety:Transparent Habits:Columnar - Forms columns, Crystalline - Coarse - Occurs as well-formed coarse sized crystals., Striated - Parallel lines on crystal surface or cleavage face. Hardness:7 - Quartz Luminescence:Non-fluorescent. Luster:Vitreous (Glassy) Streak:whiteMore details...