KS8313 Biotite Molecular Model

Biotite Biotite is a common phyllosilicate mineral within the mica group, with the approximate chemical formula K(Mg,Fe) 3AlSi 3O 10(OH) 2. More generally, it refers to the dark mica series, primarily a solid-solution series between the iron-endmember annite, and the magnesium-endmember phlogopite; more aluminous end-members include siderophyllite. Biotite was named by J.F.L. Hausmann in 1847 in honor of the French physicist Jean-Baptiste Biot, who, in 1816, researched the optical properties of mica, discovering many properties. Biotite is a sheet silicate. Iron, magnesium, aluminum, silicon, oxygen, and hydrogen form sheets that are weakly bound together by potassium ions. It is sometimes called "iron mica" because it is more iron-rich than phlogopite. It is also sometimes called "black mica" as opposed to "white mica" (muscovite) – both form in some rocks, and in some instances side-by-side. Biotite is found in a wide variety of igneous and metamorphic rocks. For instance, biotite o