Fluorophlogopite

Fluorophlogopite is a mineral species belonging to the mica group. It is a potassium, magnesium, aluminum silicate hydroxide fluoride that belongs to the phlogopite series of micas and the fluorine end member of the biotite-phlogopite series. It is structurally identical to phlogopite with the exception of having fluorine atoms instead of hydroxyl groups at certain atomic sites.

Characteristics

Fluorophlogopite is a yellow to dark brown mineral that exhibits a pearly luster. It is transparent to translucent and has a hardness of 2.5-3 on the Mohs scale. It has a perfect basal cleavage, meaning it can be split into thin sheets along one plane. The mineral is monoclinic, meaning it has one two-fold axis of rotation and one mirror plane.

Occurrence

Fluorophlogopite is a rare mineral that is found in ultra-potassic igneous rocks, and in metamorphosed limestone and dolomite. It is also found in carbonatites, a rare type of igneous rock. Notable localities include Mont Saint-Hilaire, Quebec, Canada; Långban, Sweden; and Kola Peninsula, Russia.

Uses

Due to its heat resistance and electrical insulating properties, fluorophlogopite is used in a variety of industrial applications. It is used in the manufacture of insulation for electrical wires and in heat-resistant composites. It is also used in the production of certain types of glass and ceramics.

See also

• List of minerals
• Silicate minerals
• Phlogopite
• Biotite