The silicate minerals make up the largest and most important class of rock-forming minerals, constituting approximately 90 percent of the crust of the Earth. They are classified based on the structure of their silicate group which contain different ratios of silicon and oxygen.
Sorosilicates (from Greek σωρός sōros, heap, mound) have isolated double tetrahedra groups with (Si2O7)6− or a ratio of 2:7. Nickel-Strunz classification: 09.B
Cyclosilicates (from Greek κύκλος kuklos, circle), or ring silicates, have linked tetrahedra with (TxO3x)2x- or a ratio of 1:3. These exist as 3-member (T3O9)6- and 6-member (T6O18)12- rings, where T stands for a tetrahedrally coordinated cation. Nickel-Strunz classification: 09.C
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.
Cyclosilicate, [Si6O18]- 6-membered single rings, beryl (red: Si, blue: O)
Cyclosilicate, [Si3O9]- 3-membered single ring, benitoite
Cyclosilicate, [Si4O12]- 4-membered single ring, papagoite
Cyclosilicate, [Si9O27]- 9-membered ring, eudialyte
Cyclosilicate, [Si6O18]- 6-membered double ring, milarite
Inosilicates (from Greek ις is [genitive: ινος inos], fibre), or chain silicates, have interlocking chains of silicate tetrahedra with either SiO3, 1:3 ratio, for single chains or Si4O11, 4:11 ratio, for double chains. Nickel-Strunz classification: 09.D
Inosilicate, pyroxene family, with 2-periodic single chain (Si2O6), diopside
Inosilicate, clinoamphibole, with 2-periodic double chains (Si4O11), tremolite
Inosilicate, unbranched 3-periodic single chain of wollastonite
Inosilicate with 5-periodic single chain, rhodonite
Inosilicate with cyclic branched 8-periodic chain, pellyite
The word comes from the Greek word phyllon, which means "leaf".
Phyllosilicate, mica group, muscovite (red: Si, blue: O)
Phyllosilicate, single net of tetrahedra with 4-membered rings, apophyllite-(KF)-apophyllite-(KOH) series
Phyllosilicate, single tetrahedral nets of 6-membered rings, pyrosmalite-(Fe)-pyrosmalite-(Mn) series
Phyllosilicate, single tetrahedral nets of 6-membered rings, zeophyllite
Phyllosilicate, double nets with 4- and 6-membered rings, carletonite
Tectosilicates, or "framework silicates," have a three-dimensional framework of silicate tetrahedra with SiO2 or a 1:2 ratio. This group comprises nearly 75% of the crust of the Earth. Tectosilicates, with the exception of the quartz group, are aluminosilicates. Nickel-Strunz classification: 09.F and 09.G, 04.DA (Quartz/ silica family)
Sorosilicate (Si2O7), as in suolunite
Tectosilicate, aluminosilicate 3-D network, zeolite family, synthetic zeolite ZSM-5
Silica family (SiO2 3-D-network), β-quartz
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