Axinite

AXINITE (from the Greek word "axine", which means "axe"; has been named after the form of the crystals * EN: axinite; DE: Axinit; FR: axinite; ES: axinita; RU: аксинит) is the mineral of the subclass of the (cyclosilicates) ring silicates, common boroaluminosilicate of the calcium, iron, and manganese, Ca2 (Fe2+, Mn2+) Al2 [Si4Ol2] • [BO3] (OH). According to the ratio of the Fe and Mn in the axinite, they distinguish the ferroaxinite, manganaxinite (north-ginite) and tinzenite (high-manganese axinite); there are known the magnesium containing axinites.

It crystallizes in the triclinic system with the formation of the wedge shaped crystals. The cleavage is perfect along the three directions. The colour is purple, gray, to brown. The hardness is 6.5-7. The density is 3250-3300 kilograms per cubic metre.

Axinite is the characteristic mineral of the metasomatic rocks (endoskarns, skarnoids and hornfels) and less often of the hydrothermal veins. It often accompanies the contact-metasomatic deposits of the ores of the boron, tin, iron, copper, lead, zinc, and others.