Massive Biotite Mica specimens, collected from Arendal, Norway. These specimens depict a “massive” crystal structure, as opposed to the more commonly seen sheets. Like all biotite mica, these specimens are dark in colour, exhibiting a dark grey to black hue. Mica is one of the most common mineral groups, with biotite being the most abundant member. Biotite is very common in igneous and metamorphic rocks, with the dark minerals in granites, pegmatites and gneiss often being due in some part to the presence of this black mica. This massive biotite are available in limited supply so we recommend you move fast if you wish to add a piece to your collection. Supplied in a white card tray with information label.