Axinite
Mineral Ca2(Fe,Mn,Mg)Al2BSi4O15(OH)
Also called Axinite-(Fe), Ferro-axinite, Axinite-(Mn), Manganaxinite, Axinite-(Mg), Magnesio-axinite, and Tinzenite
About it
Thin, sharp-edged crystals shaped like axe blades, usually clove to plum brown; a group of closely related species. Bourg d'Oisans, France, Dalnegorsk, Russia, and Baja California.
- Type
- Mineral
- Group
- Silicate (sorosilicate), axinite group
- Formula
- Ca2(Fe,Mn,Mg)Al2BSi4O15(OH)
- Hardness (Mohs)
- 6.5–7
- Specific gravity
- 3.18–3.36
- Streak
- white
- Lustre
- vitreous (glassy)
- Crystal system
- Triclinic
- Colours
- clove brown, violet-brown, plum, honey yellow, grey, blue
- Transparency
- transparent, translucent
- Cleavage and fracture
- good in one direction
Typical values: real specimens vary. For more, see mindat.org.