image BXO35.jpg
geological walk, Blease Fell, Threlkeld, Cumbria, NY2927 -- Rock, hand specimen of granite, from the exposure in Sinen Gill, Blease Fell, Threlkeld, Cumberland, NY30042814, 21 October 2012.
The specimen was taken from the stream bed below the waterfall over the exposed granite.
Ordovician or Lower Devonian.
The grey crystals are quartz; silcon dioxide, Si02.
The white crystals are feldspars; sodium aluminium silicate, NaAlSi3O8, or potassium aluminium silicate, KAlSi3O8, or calcium aluminium silicate, CaAl2Si2O3.
The black crystals are biotie or hornblende, complicated lattice silicates.
(photo 21.10.2012)