High-Temperature Beryl from Vugless Granite Pegmatites of the Suprunovskoye Deposit, Irkutsk Oblast, Russia

Resumo

New data were obtained on the chemical composition of beryl from the Suprunovskoye deposit (wt %): 66.10 SiO₂, 0.51 Na₂O, 17.99 Al₂O₃, 0.37 MgO, 0.03 K₂O, 0.02 CaO, 0.58 FeO, and 13.70 BeO (calculated). Fluid and melt inclusions were investigated for the first time in this mineral. It was found that the beryl was formed during late stages of granite magmatism from a specific pegmatite silicate melt or a water–silicate liquid enriched in water (>7 wt %), heavy REE (La/Yb = 0.48), and lithium, and depleted in fluorine and boron at a temperature of ~700°C and a pressure of ~6 kbar.