Prehnite can form prismatic

This is a spectacular Calcite specimen mined in La Unión

Size: 8x5mm

Product ID: HLGY12022  (Appraised at $ 720

Weight: 111 Grams / 4 Ounces

Biotite Mica Book | Black Crystal | 68 Grams | Ontario, Canada | SO24 Albite Prehnite can form prismaticThis 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.