Biotite is an essential phenocryst in some varieties of lamprophyre. Biotite is occasionally found in large cleavable crystals, especially in pegmatite veins, as in New England, Virginia and North Carolina USA.

Biotite is a rock-forming mineral found in a wide range of crystalline igneous rocks such as granite, diorite, gabbro, peridotite, and pegmatite. It also forms under metamorphic conditions when …

Named in 1847 by Johann Friedrich Ludwig Hausmann in honour of the French physicist, mathematician, meteoriticist, astronomer, and mineralogist, Jean-Baptiste Biot [April 21, 1774, Paris, …

Apr 22, 2018 · Biotite is the most common mica mineral and also known as black mica, a silicate mineral in the common mica group. Approximate chemical formula K (Mg, Fe). It can be found in massive …

Sep 29, 2015 · Biotite is a black mica mineral found in many rocks. Discover its key traits, varieties and role in igneous and metamorphic rocks.

Jun 9, 2025 · Biotite is a dark-colored mineral found in many rocks and is also known as black mica. Biotite is used to date rocks using argon-argon or potassium-argon dating methods. Mica, including …

Biotite is a very common form of mica. It is named in honor Jean Baptiste Biot (1774 - 1862), a French physicist, mathematician, and astronomer who researched the mica minerals for their optical properties.

Biotite, also known, as ‘black mica’ is a rock-forming femic phyllosilicate that occurs in several igneous and metamorphic rocks. The mineral was named in honor of the French scientist Jean-Baptiste Biot, …

Biotite, a silicate mineral in the common mica group. It is abundant in metamorphic rocks (both regional and contact), in pegmatites, and also in granites and other intrusive igneous rocks.

Has several polytypes (1M, 3T, 2M1). Biotite is now a group name for phlogopite, siderophyllite and eastonite. Common world wide. Link to MinDat.org Location Data. Named in 1847 after the French …