AXINITE (-Fe) - FERROAXINITE , ACTINOLITE, QUARTZ

Axinite is a mineral that ranges in color from brown to violet-brown, or reddish-brown, and belongs to a group characterized by bladed formations. It is composed of calcium aluminium boro-silicate, with the chemical formula (Ca,Fe,Mn)3Al2BO3Si4O12OH. Notably, axinite exhibits both pyroelectric and piezoelectric properties.

The axinite group consists of the following varieties:

Axinite-(Fe), also known as ferroaxinite, has the formula Ca2Fe2+Al2BOSi4O15(OH) and is rich in iron, displaying colors such as clove-brown, brown, plum-blue, and pearl-gray.

Axinite-(Mg), or magnesioaxinite, is represented by the formula Ca2MgAl2BOSi4O15(OH) and is rich in magnesium, appearing in shades from pale blue to pale violet, as well as light brown to light pink.

Axinite-(Mn), referred to as manganaxinite, has the formula Ca2Mn2+Al2BOSi4O15(OH) and is rich in manganese, showcasing colors like honey-yellow, clove-brown, and brown to blue.

Tinzenite, with the formula (CaFe2+Mn2+)3Al2BOSi4O15(OH), is an iron-manganese intermediate that can be yellow or brownish yellow-green.

Additionally, axinite is occasionally utilized as a gemstone.