The pegmatites of the Shingus-Bulochi
field commonly have peripheral fine-grained granite or alpite margins and coarse-grained central areas with vugs and miarolitic cavities from 5 cm to 1 m across. Transparent pale-blue gem-quality crystals of beryl
, accompanied by euhedral feldspar, quartz, schorl, and mica are found in cavities and may form part of the pegmatite matrix.
In some Bulochi pegmatites, colourless topaz
, green and brown tourmaline
, and morganite
as well as lepidolite
Ref: E.Ya. Kievlenko, Geology of gems, 2003, p. 110