.8" Brown Axinite-(Fe) Crystal Specimen - Olivia Mine, Mexico

Axinite is a subgroup under the silicate group of minerals, with three possible mineral compositions. The inclusive formula, encompassing all possible mineral member combinations, is (Ca,Fe,Mg,Mn)3Al2BSi4O15(OH). The presence of one listed alkaline or transitional element will effect the structure and colors displayed by the axinite crystal. It typically forms thin, sharp triclinic crystals, with colors ranging anywhere from a light yellow-brown to various shades of blue and green. The group name is derived from the Greek word 'axina', meaning axe, to describe the group's bladed crystal habit.