Cyclosilicates

The cyclosilicates form chains as in the inosilicates except that the chains link back around on themselves to form rings. The rings can be made from a minimum of three tetrahedrons up to eight membered rings. The symmetry of the rings is reflected in the symmetry of the minerals.

There are several gemstones in this subclass which is due to the general high hardness, luster, and durability of the minerals.

Minerals

Axinite
Beryl
Chrysocolla
Cordierite
Tourmaline

Mineral Photos courtesy of R.Weller/Cochise College