The morphology and physical properties of island silicate minerals are different due to the different forms of silica backbone. In island silicates with isolated tetrahedrons, due to the equiaxed nature of the silicon-oxygen tetrahedron, mineral crystals have an approximately equiaxed shape, with low birefringence, weak pleochroism and absorption, and often have Moderate to incomplete multidirectional cleavage. In addition, due to the high density of atoms in the structure, it has the characteristics of high hardness, high specific gravity and high refractive index. The situation of bitetrahedral island silicate minerals is not exactly the same. The shape of the crystal tends to be elongated. The hardness and refractive index of the mineral are slightly lower, and show a slightly larger anisotropy. The birefringence, pleochroism and absorption are all enhanced. The hardness, specific gravity and refractive index of island silicate minerals containing water or with additional anion are reduced. Silicate minerals with cyclic structure are often trigonal, hexagonal, tetragonal plate-like and columnar crystals, which are related to the symmetry of the ring itself in the crystal structure.
In addition, although the rings themselves have trigonal, hexagonal, or tetragonal symmetry, their symmetry is often reduced due to the different ways they are connected to the metal cations in the crystal structure, and they are in an orthogonal (orthogonal), monoclinic or triclinic crystal system. But the shape still often presents false three-party, false six-party or false four-party symmetry. The atomic packing density, specific gravity, hardness, and refractive index of cyclic silicate minerals are generally slightly lower than those of island silicate minerals. In addition, the anisotropy of the ring itself results in the anisotropy of the morphology and physical properties of the ring-shaped silicate mineral, which is slightly greater than that of the island-shaped silicate mineral, but is higher than that of the chain and layered structure. Silicate minerals are much smaller.