sorosilicates

Disilicates (or sorosilicates) have two tetrahedra sharing one oxygen atom.

Minerals of the melilite group are sorosilicates.

Sorosilicates, also termed disilicates, have tetrahedron-tetrahedron bonding at one oxygen, which results in a 2:7 ratio of silicon to oxygen.

Sorosilicates (double tetrahedra) - [SiO], e.g. epidote, melilite group.

Other examples of sorosilicates include lawsonite, a metamorphic mineral forming in the blueschist facies (subduction zone setting with low temperature and high pressure), vesuvianite, which takes up a significant amount of calcium in its chemical structure.

Julgoldites, along with more common minerals like epidote and vesuvianite, belong to the subclass of sorosilicates, the rock-forming minerals that contain SiO tetrahedra that share a common oxygen to form SiO ions with a charge of 6- (Deer et al., 1996).