Dimensions:  103x35x52 mm / 4

Dimensions: 46x29x34 mm / 1

This is a beautiful piece of natural Agate from Uruguay

Size:  25 mm incl

Biotite Mica Book | Black Crystal | 275.6 Grams | Ontario, Canada | SO24 Wolframite Dimensions: 103x35x52 mm / 4This is a sharp, beautiful, black Biotite crystal book from the Calcite Vein Dikes of the Grenville Geological Province Ontario, Canada. This biotite has classic crystal shape and attractive dark black coloration. This specimen is a great example of both, Biotite is rarely considered a valuable mineral specimen, but it can accompany other minerals and compliment them. In Bancroft, Ontario Biotite forms large crystals with green apatite and hornblende.