Silicate minerals

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The silicate minerals make up the largest and most important class of rock-forming minerals. They are classified based on the structure of their silicate ion group.

Subclasses:

1 Nesosilicates
2 Sorosilicates
3 Cyclosilicates
4 Inosilicates
- 4.1 Single chain inosilicates:
- 4.2 Double chain inosilicates:
5 Phyllosilicates
6 Tectosilicates
7 References and external links

[edit] Nesosilicates

Nesosilicates (or orthosilicates) have SiO₄ tetrahedra that are isolated and connected by interstitial cations.

Phenacite group
- Phenacite - Be₂SiO₄
- Willemite - Zn₂SiO₄
Olivine group
- Forsterite - Mg₂SiO₄
- Fayalite - Fe₂SiO₄
Garnet group
- Pyrope - Mg₃Al₂Si₃O₁₂
- Almandine - Fe₃Al₂Si₃O₁₂
- Spessartine - Mn₃Al₂Si₃O₁₂
- Grossular - Ca₃Al₂Si₃O₁₂
- Andradite - Ca₃Fe₂Si₃O₁₂
- Uvarovite - Ca₃Cr₂Si₃O₁₂
- Hydrogrossular - Ca₃Al₂Si₂O₈(SiO₄)_1-m(OH)_4m
Zircon group
- Zircon - Zr₂SiO₄
- Thorite - (Th,U)₂SiO₄
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)(F,OH)₂
- Humite - Mg₇(SiO₄)(F,OH)₂
- Clinohumite - Mg₉(SiO₄)(F,OH)₂
Datolite - CaBSiO₄(OH)
Titanite - CaTiSiO₅
Chloritoid - (Fe,Mg,Mn)₂Al₄Si₂O₁₀(OH)₄

[edit] Sorosilicates

Sorosilicates have isolated double tetrahedra groups with Si₂O₇ or a ratio of 2:7.

Hemimorphite (calamine) - Zn₄Si₂O₇(OH)₂·H₂O
Lawsonite - CaAl₂Si₂O₇(OH)₂·H₂O
Ilvaite - CaFe²⁺₂Fe³⁺Si₂O₇O(OH)
Epidote group
- Zoisite - Ca₂(Al,OH)A_l2(SiO₄)₃
- Clinozoisite - Ca₂Al₃(O,OH,SiO₄,Si₂O₇)
- Epidote - Ca₂(Al,Fe)₃(SiO₄)₃(OH)
- Allanite - Ca(Ce,La,Y,Ca)Al₂(Fe²⁺,Fe³⁺)(SiO₄)(Si₂O₇)O(OH)
Vesuvianite (idocrase) - Ca₁₀(Mg,Fe)₂Al₄(SiO₄)₅(Si₂O₇)₂(OH)₄

[edit] Cyclosilicates

Cyclosilicates, ring silicates, have linked tetrahedra with Si_xO_3x or a ratio of 1:3.

Axinite - (Ca,Fe,Mn)₃Al₂BO₃Si₄O₁₂OH
Beryl - Be₃Al₂(SiO₃)₆
Cordierite - (Mg,Fe)₂Al₄Si₅O₁₈
Tourmaline - (Na,Ca)(Al,Li,Mg)_3-(Al,Fe,Mn)₆(Si₆O₁₈)(BO₃)₃(OH)₄

[edit] Inosilicates

Inosilicates, 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.

[edit] 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 - Ca₂NaH(SiO³)₃

[edit] 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
  - ActinoliteCa₂(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)
  - Riebeckite (asbestos) - Na₂Fe²⁺₃Fe³⁺₂Si₈O₂₂(OH)₂
  - Arfvedsonite - Na₃(Fe,Mg)₄FeSi₈O₂₂(OH)₂

[edit] Phyllosilicates

Phyllosilicates, sheet silicates, form parallel sheets of silicate tetrahedra with Si₂O₅ or a 2:5 ratio.

Serpentine group
- Antigorite - Mg₃Si₂O₅(OH)₄
- Chrysotile - Mg₃Si₂O₅(OH)₄
- Lizardite - Mg₃Si₂O₅(OH)₄
Clay mineral group
- Kaolinite - Al₂Si₂O₅(OH)₄
Talc - Mg₃Si₄O₁₀(OH)₂
Pyrophyllite - Al₂Si₄O₁₀(OH)₂
Mica group
- Muscovite - KAl₂(AlSi₃O₁₀)(OH)₂
- Phlogopite - KMg₃Si₄O₁₀(OH)₂
- Biotite - K(Mg,Fe)₃(AlSi₃O₁₀)(OH)₂
- Lepidolite - K(Li,Al)_2-3(AlSi₃O₁₀)(OH)₂
- Margarite - CaAl₂(Al₂Si₂O₁₀)(OH)₂
Chlorite group
- Chlorite - (Mg,Fe)₃(Si,Al)₄O₁₀(OH)₂•(Mg,Fe)3(OH)₆

[edit] Tectosilicates

Tectosilicates, or "framework silicates", have a three-dimensional framework of silicate tetrahedra with SiO₂ or a 1:2 ratio. This is the largest group, comprising nearly 75% of the crust of the Earth.

Quartz group
- Quartz - SiO₂
- Tridymite - SiO₂
- Cristobalite - SiO₂
- Opal - SiO₂·nH₂O
Feldspar group
- Potassium-feldspars
  - Microcline - KAlSi₃O₈
  - Orthoclase - KAlSi₃O₈
  - Sanidine - KAlSi₃O₈
    - Anorthoclase - (Na,K)AlSi₃O₈
- 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 group
- Leucite - KAlSi₂O₆
- Nepheline - (Na,K)AlSiO₄
- Sodalite - Na₈(AlSiO₄)₆Cl₂
- 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 group
- Natrolite - Na₂Al₂Si₃O₁₀•2H₂O
- Chabazite - CaAl₂Si₄O₁₂•6H₂O
- Heulandite - CaAl₂Si₇O₁₈•6H₂O
- Stilbite - NaCa₂Al₅Si₁₃O₃₆•17H₂O