Abstract
Virgilite is hexagonal, P6222 or P6422; a = 5.132, c = 5.454A; n = 1.520, uniaxial (−). Cell content of the crystals studied is Li0.61 (Si2.37Al0.60Fe0.02P0.01)O6. Virgilite is found in volcanic glass of unusual composition from Macusani, Peru. It is the only naturally-occurring representative of the solid-solution series between β-quartz (Qz) and LiAlSi2O6 (Sp) with a stuffed β-quartz structure. The composition of our material corresponds to Sp61Qz39.
This content is PDF only. Please click on the PDF icon to access.
You do not have access to this content, please speak to your institutional administrator if you feel you should have access.