SILICATE MINERALS

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:

Contents

Nesosilicates or Isosilicates

Sorosilicates

Cyclosilicates

Inosilicates

Single chain inosilicates:

Double chain inosilicates:

Phyllosilicates

Tectosilicates

References and external links

Nesosilicates or Isosilicates

'''Nesosilicates''' (or ''orthosilicates'') have isolated [SiO₄]⁴⁻

tetrahedra that are connected only by interstitial cations.

★ Phenacite group

★
★ Phenacite - Be₂SiO₄

★
★ Willemite - Zn₂SiO₄

★ Olivine group

★
★ Forsterite - Mg₂SiO₄

★
★ Fayalite - Fe₂SiO₄

★ Garnet group

★
★ Pyrope - Mg₃Al₂()₃

★
★ Almandine - Fe₃Al₂()₃

★
★ Spessartine - Mn₃Al₂()₃

★
★ Grossular - Ca₃Al₂()₃

★
★ Andradite - Ca₃Fe₂()₃

★
★ Uvarovite - Ca₃Cr₂()₃

★
★ 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

Sorosilicates

'''Sorosilicates''' have isolated double tetrahedra groups with (Si₂O₇)⁶⁻ or a ratio of 2:7.

★ 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)

★ Vesuvianite (idocrase) - Ca₁₀(Mg,Fe)₂Al₄(SiO₄)₅(Si₂O₇)₂(OH)₄

Cyclosilicates

'''Cyclosilicates''', ring silicates, have linked tetrahedra with (Si_xO_3x)^2x- or a ratio of 1:3. These exists as 3-member (Si₃O₉)^6-, 4-member (Si₄O₁₂)^8- and 6-member (Si₆O₁₈)^12- rings.

★ 3-member ring

★
★ Benitoite - BaTi(Si₃O₉)

★ 4-member ring

★
★ Axinite - (Ca,Fe,Mn)₃Al₂(BO₃)(Si₄O₁₂)(OH)

★ 6-member ring

★
★ 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

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.

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

★
★
★ 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

Phyllosilicates

'''Phyllosilicates''', sheet silicates (from Greek φύλλον ''phyllon'', leaf), 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

Tectosilicates

'''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.



★ Quartz group

★
★ Quartz - SiO₂

★
★ Tridymite - SiO₂

★
★ Cristobalite - SiO₂

★ Feldspar group

★
★ Alkali-feldspars

★
★
★ Potassium-feldspars

★
★
★
★ Microcline - KAlSi₃O₈

★
★
★
★ Orthoclase - KAlSi₃O₈

★
★
★
★ Sanidine - KAlSi₃O₈

★
★
★ Anorthoclase - (Na,K)AlSi₃O₈

★
★
★ 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 group

★
★ Analcime - NaAlSi₂O₆·H₂O

★
★ 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 group

★
★ Natrolite - Na₂Al₂Si₃O₁₀•2H₂O

★
★ Chabazite - CaAl₂Si₄O₁₂•6H₂O

★
★ Heulandite - CaAl₂Si₇O₁₈•6H₂O

★
★ Stilbite - NaCa₂Al₅Si₁₃O₃₆•17H₂O

References and external links

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

★ Hurlbut, Cornelius S.; Klein, Cornelis, 1985, ''Manual of Mineralogy'', 20th ed., ISBN 0-471-80580-7

★ Mineral gallery

★ Minerals.net

★ mindat.org mineral database

★ Webmineral.com