Axinite
Encyclopedia
Axinite is a brown to violet-brown, or reddish-brown bladed group of mineral
s composed of calcium
aluminium
boro
-silicate
, (Ca,Fe,Mn)3Al2BO3Si4O12OH. Axinite is pyroelectric
and piezoelectric.
The axinite group includes:
Mineral
A mineral is a naturally occurring solid chemical substance formed through biogeochemical processes, having characteristic chemical composition, highly ordered atomic structure, and specific physical properties. By comparison, a rock is an aggregate of minerals and/or mineraloids and does not...
s composed of calcium
Calcium
Calcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust...
aluminium
Aluminium
Aluminium or aluminum is a silvery white member of the boron group of chemical elements. It has the symbol Al, and its atomic number is 13. It is not soluble in water under normal circumstances....
boro
Boron
Boron is the chemical element with atomic number 5 and the chemical symbol B. Boron is a metalloid. Because boron is not produced by stellar nucleosynthesis, it is a low-abundance element in both the solar system and the Earth's crust. However, boron is concentrated on Earth by the...
-silicate
Silicon
Silicon is a chemical element with the symbol Si and atomic number 14. A tetravalent metalloid, it is less reactive than its chemical analog carbon, the nonmetal directly above it in the periodic table, but more reactive than germanium, the metalloid directly below it in the table...
, (Ca,Fe,Mn)3Al2BO3Si4O12OH. Axinite is pyroelectric
Pyroelectricity
Pyroelectricity is the ability of certain materials to generate a temporary voltage when they are heated or cooled. The change in temperature modifies the positions of the atoms slightly within the crystal structure, such that the polarization of the material changes. This polarization change...
and piezoelectric.
The axinite group includes:
- Axinite-(Fe), ferro-axinite, iron rich, lilac brown to black
- Axinite-(Mg), magnesio-axinite, magnesium rich, pale blue to gray
- Axinite-(Mn), manganaxinite, manganese rich, yellow-orange
- Tinzenite, iron – manganese intermediate, yellow