silicate minerals - Sorosilicates, Phyllosilicates, Tectosilicates, References and external links

A group of minerals constituting about 95% of the Earth's crust, and containing silicon and oxygen combined with one or more other elements. Structurally they are all based on SiO₄, the tetrahedron, and most are complex polymeric structures of tetrahedra. They are classified according to the degree of polymerization, from silicates containing isolated SiO₄ groups (eg olivines, garnets) to rings (eg beryl) to chain silicates (eg pyroxenes (single chains) and amphiboles (double chains)), sheets (eg micas, clays), and three-dimensional frameworks (eg quartz, feldspars).

Phenakite group Phenakite Willemite Olivine group Forsterite Fayalite Garnet group Pyrope Almandine Spessartine Grossular Andradite Uvarovite Hydrogrossular Zircon group Zircon Thorite Al2SiO5 group Andalusite Kyanite Sillimanite Dumortierite Topaz Staurolite Humite group Datolite Titanite Chloritoid

Sorosilicates

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

Single chain inosilicates:

Pyroxene group Enstatite - orthoferrosilite series Enstatite Bronzite Hypersthene Clinohypersthene Pigeonite Diopside - hedenbergite series Diopside Hedenbergite Johannsenite Augite Sodium pyroxene series Jadeite Omphacite Acmite (aegirine) Spodumene Pyroxenoid group Wollastonite Rhodonite Pectolite

Double chain inosilicates:

Amphibole group Anthophyllite Cumingtonite series Cummingtonite Grunerite Tremolite series Tremolite Actinolite Hornblende Sodium amphibole group Glaucophane Riebeckite Crocidolite - asbestos Arfvedsonite

Phyllosilicates

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

Serpentine group Antigorite Chrysotile Clay mineral group Kaolinite Smectite Montmorillonite Illite Talc Pyrophyllite Mica group Muscovite Phlogopite Biotite Lepidolite Margarite Chlorite group Apophyllite Prehnite

Tectosilicates

Tectosilicates, or "framework silicates", have a three-dimensional framework of silicate tetrahedra with SiO2 or a 1:2 ratio.

Quartz group Quartz Tridymite Cristobalite Opal Feldspar group Potassium-feldspars Microcline Orthoclase Sanidine Plagioclase feldspars Albite Oligoclase Andesine Labradorite Bytownite Anorthite Feldspathoid group Leucite Nepheline Sodalite Lazurite Petalite Scapolite group Marialite Meionite Analcime Zeolite group Natrolite Chabazite Heulandite Stilbite

References and external links

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