What are nesosilicate in mineralogy ?
Nesosilicates : definition
Nesosilicates are a subclass of silicates, they are formed of independent tetrahedra (SiO4)4- linked together by cations Mg, Fe, Mn, etc... Their name comes from the Greek nesos (island).
Because of this independence and the absence of constraining sequences, the neosilicates have a high symmetry (many belong to the cubic and tetragonal system), and few clear cleavages. The degree of substitution of Si by Al is usually low, except for the group of alumina silicates.
Nesosilicates include around 175 minerals, including geologically essential groups and minerals : garnets, olivine, zircon, topaz, staurolite, (alumina silicates : andalusite, kyanite, sillimanite), etc...
Because of this independence and the absence of constraining sequences, the neosilicates have a high symmetry (many belong to the cubic and tetragonal system), and few clear cleavages. The degree of substitution of Si by Al is usually low, except for the group of alumina silicates.
Nesosilicates include around 175 minerals, including geologically essential groups and minerals : garnets, olivine, zircon, topaz, staurolite, (alumina silicates : andalusite, kyanite, sillimanite), etc...