Mineral Species: Axinite

Chemical Formula: (Ca,Fe,Mn)3Al2BO3Si4O12OH

Chemical Name: Calcium Iron Manganese Borosilicate

Mineral Class: Sorosilicate

Mineral Notes: Axinite is actually a series name for a group of isostructural minerals. All have the same structure but are different in terms of chemistry. They are named for their respective enrichment in iron, magnesium and manganese, except for the iron manganese intermediate Tinzenite. They differ slightly in color and specific gravity, which makes individual identification very difficult wiothout advanced analytical equipment. Axinite produced unusual flattened, platy crystals. It is triclinic, which means that it has no symmetry planes or axes of rotation. It does, however, posses a center of symmetry.

Description: Lustrous, clove-brown Axinite crystals on matrix. Although mostly small, the crystal form and habit is exemplary. An excellent specimen of a rare and complex mineral.

Location: Bourg d'Oisans, Isère, Rhône-Alpes, France