What are silicates in mineralogy ?

Silicates : definition

Silicates constitute the essential mineralogical class, comprising minerals made up of a sequence of elementary tetrahedra (SiO4)4-, the fundamental building block of the crystalline structure. The very strong Si-O bond can be considered as the cement of the earth's crust.

These tetrahedra can be free, assembled by different cations (Mg2+, Fe2+, Ca2+, Mn2+, K+, Na+...), or linked together by their vertices. There are 6 ways to achieve these sequences depending on the number of oxygen ions involved, giving 6 structural configurations which are the basis of the subdivision of silicates into six subclasses :

- nesosilicates with isolated tetrahedra (olivines, garnets, etc...)
- sorosilicates with tetrahedra linked in pairs (epidote, vesuvianite, etc...)
- cyclosilicates with ring structures involving at least 3 tetrahedra (tourmalinesberyls, etc...)
- inosilicates, made up of single or double chains (ribbons), (pyroxenes, amphiboles, etc...)
- phyllosilicates with tetrahedra assembled in layers (micas, clays, talc, chlorite, etc...).
- tectosilicates with tetrahedra bound by their four vertices in the three directions of space (quartz, feldspars, feldspathoids, etc...).

ReCaptcha

This service is used to secure web forms of our website and required if you want to contact us. By accepting it you agree to Google's privacy policy: https://policies.google.com/privacy

Google Analytics

Google Analytics is a service used on our website that tracks, reports traffic and measures how users interact with our website content in order for us to improve it and provide better services.

Facebook

Our website allows you to like or share its content on Facebook social network. By activating and using it you agree to Facebook's privacy policy: https://www.facebook.com/policy/cookies/

YouTube

Integrated videos provided by YouTube are used on our website. By accepting to watch them you agree to Google's privacy policy: https://policies.google.com/privacy

Twitter

Integrated tweets and share services of Twitter are used on our website. By accepting and using these you agree to Twitter's privacy policy: https://help.twitter.com/en/rules-and-policies/twitter-cookies

PInterest

Our website allows you to share its content on PInterest social network. By activating and using it you agree to PInterest's privacy policy: https://policy.pinterest.com/en/privacy-policy/