Outstanding colorless prismatic crystals of the extremely rare mineral virgilite from the type and only known locality worldwide in Peru (Macusani, Carabaya Province, Puno Department, Peru). Ex Vandenbroucke Museum collection from Waregem, Belgium. — Photo: David Hospital · CC BY-SA 4.0
Virgilite
Virgilite is an IMA-recognized mineral species in the silicate class, with the chemical formula LiAlSi₂O₆.
It crystallizes in the hexagonal crystal system (space group P6_222). It is a member of the Quartz structural group.
Key properties: specific gravity 2.46; optically uniaxial.
IMA symbol Vir, IMA status: approved, named in 1977.
Occurs as inclusions in stream cobbles of peraluminous volcanic glass.
It is found associated with Quartz, andalusite, sillimanite, potassic feldspar, biotite, spinel.
In honor of Professor Virgil Everett Barnes (1903{), University of Texas, Austin, Texas, USA, prominent worker on tektites, impactites, and other natural glasses.