cyclosilicates

Cyclosilicates tend to be strong, with elongated, striated crystals.

The ring silicates, or cyclosilicates, only need tetrahedra to share two corners to form the cyclical structure.

Osumilite is part of the milarite group (also known as the milarite-osumilite group) of cyclosilicates.

Note that the ring in axinite contains two B and four Si tetrahedra and is highly distorted compared to the other 6-member ring cyclosilicates.

Other cyclosilicates include beryl, AlBeSiO, whose varieties include the gemstones emerald (green) and aquamarine (bluish).