Silicate minerals

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.

File:Chrysocolla.jpg

Phyllosilicate mineral chrysocolla

Nesosilicates or orthosilicates

File:Nesosilicates exhibit, Museum of Geology, South Dakota.jpg

Nesosilicate specimens at the Museum of Geology in South Dakota

Template:Maincat Nesosilicates (from Greek νησος nēsos, island), or orthosilicates, have isolated (insular) [SiO₄]⁴⁻ tetrahedra that are connected only by interstitial cations. Nickel-Strunz classification: 09.A

• Phenakite group
  • Phenakite - Be₂SiO₄
  • Willemite - Zn₂SiO₄
• Olivine group
  • Forsterite - Mg₂SiO₄
  • Fayalite - Fe₂SiO₄
• Garnet group
  • Pyrope - Mg₃Al₂(SiO₄)₃
  • Almandine - Fe₃Al₂(SiO₄)₃
  • Spessartine - Mn₃Al₂(SiO₄)₃
  • Grossular - Ca₃Al₂(SiO₄)₃
  • Andradite - Ca₃Fe₂(SiO₄)₃
  • Uvarovite - Ca₃Cr₂(SiO₄)₃
  • Hydrogrossular - Ca₃Al₂Si₂O₈(SiO₄)_3-m(OH)_4m
• Zircon group
  • Zircon - ZrSiO₄
  • Thorite - (Th,U)SiO₄

File:Kyanite crystals.jpg

Kyanite crystals (unknown scale)

• Al₂SiO₅ group
  • Andalusite - Al₂SiO₅
  • Kyanite - Al₂SiO₅
  • Sillimanite - Al₂SiO₅
  • Dumortierite - Al_6.5-7BO₃(SiO₄)₃(O,OH)₃
  • Topaz - Al₂SiO₄(F,OH)₂
  • Staurolite - Fe₂Al₉(SiO₄)₄(O,OH)₂
• Humite group - (Mg,Fe)₇(SiO₄)₃(F,OH)₂
  • Norbergite - Mg₃(SiO₄)(F,OH)₂
  • Chondrodite - Mg₅(SiO₄)₂(F,OH)₂
  • Humite - Mg₇(SiO₄)₃(F,OH)₂
  • Clinohumite - Mg₉(SiO₄)₄(F,OH)₂
• Datolite - CaBSiO₄(OH)
• Titanite - CaTiSiO₅
• Chloritoid - (Fe,Mg,Mn)₂Al₄Si₂O₁₀(OH)₄

Sorosilicates

File:Sorosilicates exhibit, Museum of Geology, South Dakota.jpg

Sorosilicate exhibit at Museum of Geology in South Dakota

Template:Maincat 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

• Hemimorphite (calamine) - Zn₄(Si₂O₇)(OH)₂·H₂O
• Lawsonite - CaAl₂(Si₂O₇)(OH)₂·H₂O
• Ilvaite - CaFe²⁺₂Fe³⁺O(Si₂O₇)(OH)
• Epidote group (has both (SiO₄)⁴⁻ and (Si₂O₇)⁶⁻ groups)
  • Epidote - Ca₂(Al,Fe)₃O(SiO₄)(Si₂O₇)(OH)
  • Zoisite - Ca₂Al₃O(SiO₄)(Si₂O₇)(OH)
  • Clinozoisite - Ca₂Al₃O(SiO₄)(Si₂O₇)(OH)
  • Tanzanite - Ca₂Al₃O(SiO₄)(Si₂O₇)(OH)
  • Allanite - Ca(Ce,La,Y,Ca)Al₂(Fe²⁺,Fe³⁺)O(SiO₄)(Si₂O₇)(OH)
  • Dollaseite-(Ce) - CaCeMg₂AlSi₃O₁₁F(OH)
• Vesuvianite (idocrase) - Ca₁₀(Mg,Fe)₂Al₄(SiO₄)₅(Si₂O₇)₂(OH)₄

Cyclosilicates

File:Cyclosilicate exhibit, Museum of Geology, South Dakota.jpg

Cyclosilicate specimens at the Museum of Geology, South Dakota

Template:Maincat Cyclosilicates (from Greek κύκλος kuklos, circle), or ring silicates, have linked tetrahedra with (T_xO_3x)^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

• 3-member ring
  • Benitoite - BaTi(Si₃O₉)
• 6-member ring
  • Axinite - (Ca,Fe,Mn)₃Al₂(BO₃)(Si₄O₁₂)(OH)
  • Beryl/Emerald - Be₃Al₂(Si₆O₁₈)
  • Cordierite - (Mg,Fe)₂Al₃(Si₅AlO₁₈)
  • Tourmaline - (Na,Ca)(Al,Li,Mg)_3-(Al,Fe,Mn)₆(Si₆O₁₈(BO₃)₃(OH)₄

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.

Beryll.ring.combined.png

Cyclosilicate, [Si₆O₁₈]- 6-membered single rings, beryl (red: Si, blue: O)

Benitoid.2200.png

Cyclosilicate, [Si₃O₉]- 3-membered single ring, benitoite

Papagoite.2200.png

Cyclosilicate, [Si₄O₁₂]- 4-membered single ring, papagoite

Eudialyte.2200.png

Cyclosilicate, [Si₉O₂₇]- 9-membered ring, eudialyte

Milarite.png

Cyclosilicate, [Si₆O₁₈]- 6-membered double ring, milarite

Inosilicates

Template:Maincat 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

Single chain inosilicates

• Pyroxene group
  • Enstatite - orthoferrosilite series
    • Enstatite - MgSiO₃
    • Ferrosilite - FeSiO₃
  • Pigeonite - Ca_0.25(Mg,Fe)_1.75Si₂O₆
  • Diopside - hedenbergite series
    • Diopside - CaMgSi₂O₆
    • Hedenbergite - CaFeSi₂O₆
    • Augite - (Ca,Na)(Mg,Fe,Al)(Si,Al)₂O₆
  • Sodium pyroxene series
    • Jadeite - NaAlSi₂O₆
    • Aegirine (Acmite) - NaFe³⁺Si₂O₆
  • Spodumene - LiAlSi₂O₆
• Pyroxenoid group
  • Wollastonite - CaSiO₃
  • Rhodonite - MnSiO₃
  • Pectolite - NaCa₂(Si₃O₈)(OH)

Double chain inosilicates

• Amphibole group
  • Anthophyllite - (Mg,Fe)₇Si₈O₂₂(OH)₂
  • Cumingtonite series
    • Cummingtonite - Fe₂Mg₅Si₈O₂₂(OH)₂
    • Grunerite - Fe₇Si₈O₂₂(OH)₂
  • Tremolite series
    • Tremolite - Ca₂Mg₅Si₈O₂₂(OH)₂
    • Actinolite - Ca₂(Mg,Fe)₅Si₈O₂₂(OH)₂
  • Hornblende - (Ca,Na)_2-3(Mg,Fe,Al)₅Si₆(Al,Si)₂O₂₂(OH)₂
  • Sodium amphibole group
    • Glaucophane - Na₂Mg₃Al₂Si₈O₂₂(OH)₂
    • Riebeckite (asbestos) - Na₂Fe²⁺₃Fe³⁺₂Si₈O₂₂(OH)₂
    • Arfvedsonite - Na₃(Fe,Mg)₄FeSi₈O₂₂(OH)₂

Pyroxen-chain.png

Inosilicate, pyroxene family, with 2-periodic single chain (Si₂O₆), diopside

Tremolite-chain.png

Inosilicate, clinoamphibole, with 2-periodic double chains (Si₄O₁₁), tremolite

Wollastonite-chain.png

Inosilicate, unbranched 3-periodic single chain of wollastonite

Rhodonite-chain.png

Inosilicate with 5-periodic single chain, rhodonite

Pellyite-chain.png

Inosilicate with cyclic branched 8-periodic chain, pellyite

Phyllosilicates

Template:Maincat Phyllosilicates (from Greek φύλλον phyllon, leaf), or sheet silicates, form parallel sheets of silicate tetrahedra with Si₂O₅ or a 2:5 ratio. Nickel-Strunz classification: 09.E

The word comes from the Greek word phyllon, which means "leaf".

File:KaolinUSGOV.jpg

Kaolin

• Serpentine group
  • Antigorite - Mg₃Si₂O₅(OH)₄
  • Chrysotile - Mg₃Si₂O₅(OH)₄
  • Lizardite - Mg₃Si₂O₅(OH)₄
• Clay mineral group
  • Halloysite - Al₂Si₂O₅(OH)₄
  • Kaolinite - Al₂Si₂O₅(OH)₄
  • Illite - (K,H₃O)(Al,Mg,Fe)₂(Si,Al)₄O₁₀[(OH)₂,(H₂O)]
  • Montmorillonite - (Na,Ca)_0.33(Al,Mg)₂Si₄O₁₀(OH)₂·nH₂O
  • Vermiculite - (MgFe,Al)₃(Al,Si)₄O₁₀(OH)₂·4H₂O
  • Talc - Mg₃Si₄O₁₀(OH)₂
  • Palygorskite - (Mg,Al)₂Si₄O₁₀(OH)·4(H₂O)
  • Pyrophyllite - Al₂Si₄O₁₀(OH)₂
• Mica group
  • Biotite - K(Mg,Fe)₃(AlSi₃)O₁₀(OH)₂
  • Muscovite - KAl₂(AlSi₃)O₁₀(OH)₂
  • Phlogopite - KMg₃(AlSi₃)O₁₀(OH)₂
  • Lepidolite - K(Li,Al)_2-3(AlSi₃)O₁₀(OH)₂
  • Margarite - CaAl₂(Al₂Si₂)O₁₀(OH)₂
  • Glauconite - (K,Na)(Al,Mg,Fe)₂(Si,Al)₄O₁₀(OH)₂
• Chlorite group
  • Chlorite - (Mg,Fe)₃(Si,Al)₄O₁₀(OH)₂•(Mg,Fe)₃(OH)₆

Muskovite.sheet.png

Phyllosilicate, mica group, muscovite (red: Si, blue: O)

Apophyllite.sheet.png

Phyllosilicate, single net of tetrahedra with 4-membered rings, apophyllite-(KF)-apophyllite-(KOH) series

Pyrosmalite.sheet.png

Phyllosilicate, single tetrahedral nets of 6-membered rings, pyrosmalite-(Fe)-pyrosmalite-(Mn) series

Zeophyllite.sheet.png

Phyllosilicate, single tetrahedral nets of 6-membered rings, zeophyllite

Carletonite.sheet.png

Phyllosilicate, double nets with 4- and 6-membered rings, carletonite

Tectosilicates

Template:Maincat 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)

File:Quartz oisan.jpg

Quartz

File:Lunar Ferroan Anorthosite 60025.jpg

Lunar Ferroan Anorthosite #60025 (Plagioclase Feldspar). Collected by Apollo 16 from the Lunar Highlands near Descartes Crater.

• Quartz group
  • Quartz - SiO₂
  • Tridymite - SiO₂
  • Cristobalite - SiO₂
  • Coesite - SiO₂
• Feldspar family
  • Alkali-feldspars (potassium-feldspars)
    • Microcline - KAlSi₃O₈
    • Orthoclase - KAlSi₃O₈
    • Anorthoclase - (Na,K)AlSi₃O₈
    • Sanidine - KAlSi₃O₈
    • Albite - NaAlSi₃O₈
  • Plagioclase feldspars
    • Albite - NaAlSi₃O₈
    • Oligoclase - (Na,Ca)(Si,Al)₄O₈ (Na:Ca 4:1)
    • Andesine - (Na,Ca)(Si,Al)₄O₈ (Na:Ca 3:2)
    • Labradorite - (Na,Ca)(Si,Al)₄O₈ (Na:Ca 2:3)
    • Bytownite - (Na,Ca)(Si,Al)₄O₈ (Na:Ca 1:4)
    • Anorthite - CaAl₂Si₂O₈
• Feldspathoid family
  • Nosean - Na₈Al₆Si₆O₂₄(SO₄)
  • Cancrinite - Na₆Ca₂(CO₃,Al₆Si₆O₂₄).2H₂O
  • Leucite - KAlSi₂O₆
  • Nepheline - (Na,K)AlSiO₄
  • Sodalite - Na₈(AlSiO₄)₆Cl₂
    • Hauyne - (Na,Ca)_4-8Al₆Si₆(O,S)24(SO₄,Cl)_1-2
  • Lazurite - (Na,Ca)₈(AlSiO₄)₆(SO₄,S,Cl)₂
• Petalite - LiAlSi₄O₁₀
• Scapolite group
  • Marialite - Na₄(AlSi₃O₈)₃(Cl₂,CO₃,SO₄)
  • Meionite - Ca₄(Al₂Si₂O₈)₃(Cl₂CO₃,SO₄)
• Analcime - NaAlSi₂O₆•H₂O
• Zeolite family
  • Natrolite - Na₂Al₂Si₃O₁₀•2H₂O
  • Chabazite - CaAl₂Si₄O₁₂•6H₂O
  • Heulandite - CaAl₂Si₇O₁₈•6H₂O
  • Stilbite - NaCa₂Al₅Si₁₃O₃₆•17H₂O
  • Scolecite - CaAl₂Si₃O₁₀.3H₂O
  • Mordenite - (Ca,Na₂,K₂)Al₂Si₁₀O₂₄•7H₂O

Gallery

Silicate-tetrahedron-3D-balls.png

Nesosilicate (SiO₄)

Silicate-double-tetrahedra-3D-balls.png

Sorosilicate (Si₂O₇), as in suolunite
[Ca₂Si₂O₅(OH)₂·H₂O]

Zeolite-ZSM-5-3D-vdW.png

Tectosilicate, aluminosilicate 3-D network, zeolite family, synthetic zeolite ZSM-5

Beta-quartz-CM-2D-balls.png

Silica family (SiO₂ 3-D-network), β-quartz

See also

Template:Portal

• Classification of minerals - Non silicates
• Classification of minerals - Silicates
• Silicate mineral paint

References

Template:No footnotes

• Deer, W.A.; Howie, R.A., & Zussman, J. (1992). An introduction to the rock-forming minerals (2nd ed.). London: Longman. ISBN 0-582-30094-0

      ISBN 0-582-30094-0. 

• Deer, W.A.; Howie, R.A., Wise, W.S. & Zussman, J. (2004). Rock-forming minerals. Volume 4B. Framework silicates: silica minerals. Feldspathoids and the zeolites (2nd ed.). London: Geological Society of London. p. 982 pp. 

• Hurlbut, Cornelius S. (1966). Dana's Manual of Mineralogy (17th ed.). ISBN 0-471-03288-3

      ISBN 0-471-03288-3. 

• Hurlbut, Cornelius S.; Klein, Cornelis (1985). Manual of Mineralogy (20th ed.). Wiley. ISBN 0-471-80580-7

      ISBN 0-471-80580-7. 

• Mindat.org, Dana classification
• Webmineral : Dana's New Silicate Classification

External links

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Template:Strunz ar:معادن السيليكات ca:Mineral silicat de:Silikate eo:Silikatmineraloj fa:کانی‌های سیلیکات fr:Silicate mk:Силикатни минерали ja:ケイ酸塩鉱物 pt:Silicato (minerais)