(Redirected from Orthosilicate)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:
Nesosilicates or Isosilicates
'''Nesosilicates''' (or ''orthosilicates'') have isolated [SiO
4]
4−

Kyanite crystals
tetrahedra that are connected only by interstitial cations.
★ Phenacite group
★
★
Phenacite - Be
2SiO
4
★
★
Willemite - Zn
2SiO
4
★
Olivine group
★
★
Forsterite - Mg
2SiO
4
★
★
Fayalite - Fe
2SiO
4
★
Garnet group
★
★
Pyrope - Mg
3Al
2()
3
★
★
Almandine - Fe
3Al
2()
3
★
★
Spessartine - Mn
3Al
2()
3
★
★
Grossular - Ca
3Al
2()
3
★
★
Andradite - Ca
3Fe
2()
3
★
★
Uvarovite - Ca
3Cr
2()
3
★
★
Hydrogrossular - Ca
3Al
2Si
2O
8(SiO
4)
1-m(OH)
4m
★ Zircon group
★
★
Zircon - Zr
2SiO
4
★
★
Thorite - (Th,U)
2SiO
4
★ Al
2SiO
5 group
★
★
Andalusite - Al
2SiO
5
★
★
Kyanite - Al
2SiO
5
★
★
Sillimanite - Al
2SiO
5
★
★
Dumortierite - Al
6.5-7BO
3(SiO
4)
3(O,OH)
3
★
★
Topaz - Al
2SiO
4(F,OH)
2
★
★
Staurolite - Fe
2Al
9(SiO
4)
4(O,OH)
2
★
Humite group - (Mg,Fe)
7(SiO
4)
3(F,OH)
2
★
★
Norbergite - Mg
3(SiO
4)(F,OH)
2
★
★
Chondrodite - Mg
5(SiO
4)(F,OH)
2
★
★
Humite - Mg
7(SiO
4)(F,OH)
2
★
★
Clinohumite - Mg
9(SiO
4)(F,OH)
2
★
Datolite - CaBSiO
4(OH)
★
Titanite - CaTiSiO
5
★
Chloritoid - (Fe,Mg,Mn)
2Al
4Si
2O
10(OH)
4
Sorosilicates
'''Sorosilicates''' have isolated double tetrahedra groups with (Si
2O
7)
6− or a ratio of 2:7.
★
Hemimorphite (
calamine) - Zn
4(Si
2O
7)(OH)
2·H
2O
★
Lawsonite - CaAl
2(Si
2O
7)(OH)
2·H
2O
★
Ilvaite - CaFe
2+2Fe
3+O(Si
2O
7)(OH)
★ Epidote group (has both (SiO
4)
4− and (Si
2O
7)
6− groups)
★
★
Epidote - Ca
2(Al,Fe)
3O(SiO
4)(Si
2O
7)(OH)
★
★
Zoisite - Ca
2Al
3O(SiO
4)(Si
2O
7)(OH)
★
★
Clinozoisite - Ca
2Al
3O(SiO
4)(Si
2O
7)(OH)
★
★
Tanzanite - Ca
2Al
3O(SiO
4)(Si
2O
7)(OH)
★
★
Allanite - Ca(Ce,La,Y,Ca)Al
2(Fe
2+,Fe
3+)O(SiO
4)(Si
2O
7)(OH)
★
Vesuvianite (
idocrase) - Ca
10(Mg,Fe)
2Al
4(SiO
4)
5(Si
2O
7)
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 (Si
3O
9)
6-, 4-member (Si
4O
12)
8- and 6-member (Si
6O
18)
12- rings.
★ 3-member ring
★
★
Benitoite - BaTi(Si
3O
9)
★ 4-member ring
★
★
Axinite - (Ca,Fe,Mn)
3Al
2(BO
3)(Si
4O
12)(OH)
★ 6-member ring
★
★
Beryl/
Emerald - Be
3Al
2(Si
6O
18)
★
★
Cordierite - (Mg,Fe)
2Al
3(Si
5AlO
18)
★
★
Tourmaline - (Na,Ca)(Al,Li,Mg)
3-(Al,Fe,Mn)
6(Si
6O
18)(BO
3)
3(OH)
4
Inosilicates
'''Inosilicates''', chain silicates, have interlocking chains of silicate tetrahedra with either SiO
3, 1:3 ratio, for single chains or Si
4O
11, 4:11 ratio, for double chains.
Single chain inosilicates:
★
Pyroxene group
★
★ Enstatite - orthoferrosilite series
★
★
★
Enstatite - MgSiO
3
★
★
★
Ferrosilite - FeSiO
3
★
★
Pigeonite - Ca
0.25(Mg,Fe)
1.75Si
2O
6
★
★ Diopside - hedenbergite series
★
★
★
Diopside - CaMgSi
2O
6
★
★
★
Hedenbergite - CaFeSi
2O
6
★
★
★
Augite - (Ca,Na)(Mg,Fe,Al)(Si,Al)
2O
6
★
★ Sodium pyroxene series
★
★
★
Jadeite - NaAlSi
2O
6
★
★
★
Aegirine (
Acmite) - NaFe
3+Si
2O
6
★
★
Spodumene - LiAlSi
2O
6
★ Pyroxenoid group
★
★
Wollastonite - CaSiO
3
★
★
Rhodonite - MnSiO
3
★
★
Pectolite - NaCa
2(Si
3O
8)(OH)
Double chain inosilicates:
★
Amphibole group
★
★
Anthophyllite - (Mg,Fe)
7Si
8O
22(OH)
2
★
★ Cumingtonite series
★
★
★
Cummingtonite - Fe
2Mg
5Si
8O
22(OH)
2
★
★
★
Grunerite - Fe
7Si
8O
22(OH)
2
★
★ Tremolite series
★
★
★
Tremolite - Ca
2Mg
5Si
8O
22(OH)
2
★
★
★
ActinoliteCa
2(Mg,Fe)
5Si
8O
22(OH)
2
★
★
Hornblende - (Ca,Na)
2-3(Mg,Fe,Al)
5Si
6(Al,Si)
2O
22(OH)
2
★
★ Sodium amphibole group
★
★
★
Glaucophane Na
2Mg
3Al
2Si
8O
22(OH)
★
★
★
Riebeckite (
asbestos) - Na
2Fe
2+3Fe
3+2Si
8O
22(OH)
2
★
★
★
Arfvedsonite - Na
3(Fe,Mg)
4FeSi
8O
22(OH)
2
Phyllosilicates
'''Phyllosilicates''', sheet silicates (from
Greek φύλλον ''phyllon'', leaf), form parallel sheets of silicate tetrahedra with Si
2O
5 or a 2:5 ratio.

Kaolin.
★
Serpentine group
★
★
Antigorite - Mg
3Si
2O
5(OH)
4
★
★
Chrysotile - Mg
3Si
2O
5(OH)
4
★
★
Lizardite - Mg
3Si
2O
5(OH)
4
★
Clay mineral group
★
★
Kaolinite - Al
2Si
2O
5(OH)
4
★
Talc - Mg
3Si
4O
10(OH)
2
★
Pyrophyllite - Al
2Si
4O
10(OH)
2
★
Mica group
★
★
Muscovite - KAl
2(AlSi
3O
10)(OH)
2
★
★
Phlogopite - KMg
3Si
4O
10(OH)
2
★
★
Biotite - K(Mg,Fe)
3(AlSi
3O
10)(OH)
2
★
★
Lepidolite - K(Li,Al)
2-3(AlSi
3O
10)(OH)
2
★
★
Margarite - CaAl
2(Al
2Si
2O
10)(OH)
2
★
Chlorite group
★
★
Chlorite - (Mg,Fe)
3(Si,Al)
4O
10(OH)
2•(Mg,Fe)3(OH)
6
Tectosilicates
'''Tectosilicates''', or "framework silicates", have a three-dimensional framework of silicate tetrahedra with SiO
2 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 - SiO
2
★
★
Tridymite - SiO
2
★
★
Cristobalite - SiO
2
★
Feldspar group
★
★ Alkali-feldspars
★
★
★ Potassium-feldspars
★
★
★
★
Microcline - KAlSi
3O
8
★
★
★
★
Orthoclase - KAlSi
3O
8
★
★
★
★
Sanidine - KAlSi
3O
8
★
★
★
Anorthoclase - (Na,K)AlSi
3O
8
★
★
★
Albite - NaAlSi
3O
8
★
★
Plagioclase feldspars
★
★
★
Albite - NaAlSi
3O
8
★
★
★
★
Oligoclase - (Na,Ca)(Si,Al)
4O
8 (Na:Ca 4:1)
★
★
★
★
Andesine - (Na,Ca)(Si,Al)
4O
8 (Na:Ca 3:2)
★
★
★
★
Labradorite - (Na,Ca)(Si,Al)
4O
8 (Na:Ca 2:3)
★
★
★
★
Bytownite - (Na,Ca)(Si,Al)
4O
8 (Na:Ca 1:4)
★
★
★
Anorthite - CaAl
2Si
2O
8
★
Feldspathoid group
★
★
Analcime - NaAlSi
2O
6·H
2O
★
★
Nosean - Na
8Al
6Si
6O
24(SO
4)
★
★
Cancrinite - Na
6Ca
2(CO
3,Al
6Si
6O
24).2H
2O
★
★
Leucite - KAlSi
2O
6
★
★
Nepheline - (Na,K)AlSiO
4
★
★
Sodalite - Na
8(AlSiO
4)
6Cl
2
★
★
★
Hauyne - (Na,Ca)
4-8Al
6Si
6(O,S)24(SO
4,Cl)
1-2
★
★
Lazurite - (Na,Ca)
8(AlSiO
4)
6(SO
4,S,Cl)
2
★
Petalite - LiAlSi
4O
10
★
Scapolite group
★
★
Marialite - Na
4(AlSi
3O
8)
3(Cl
2,CO
3,SO
4)
★
★
Meionite - Ca
4(Al
2Si
2O
8)
3(Cl
2CO
3,SO
4)
★
Analcime - NaAlSi
2O
6•H
2O
★
Zeolite group
★
★
Natrolite - Na
2Al
2Si
3O
10•2H
2O
★
★
Chabazite - CaAl
2Si
4O
12•6H
2O
★
★
Heulandite - CaAl
2Si
7O
18•6H
2O
★
★
Stilbite - NaCa
2Al
5Si
13O
36•17H
2O
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