Minerals in space group 68

Carpholite is a manganese silicate mineral with formula Mn2+Al2Si2O6(OH)4. It occurs as yellow clusters of slender prisms or needles. It crystallizes in the orthorhombic system.

Magnesiocarpholite is a rare magnesium-bearing inosilicate mineral in the carpholite group, with ideal formula MgAl2Si2O6(OH)4. It typically forms very slender, acicular crystals with a silky appearance. Magnesiocarpholite occurs in high-pressure, low-temperature metamorphic rocks and is used by geologists as a marker for subduction-zone conditions in magnesium-rich sedimentary rocks.

Vanadiocarpholite (Mn2+V3+AlSi2O6(OH)4) is straw yellow to brown silicate mineral. It crystallizes in the orthorhombic crystal system. It is the vanadium rich variety of carpholite (Mn2+Al2Si2O6(OH)4).