ANTHOPHYLLITE

    Class : Silicates
    Subclass : Inosilicates
    Crystal System : Orthorhombic
    Chemistry : (Mg,Fe)7Si8O22(OH)2
    Rarity : Uncommon

Anthophyllite belongs to the group of orthorhombic amphiboles and forms two series with ferro-anthophyllite and magnesio-anthophyllite. It is a typical amphibole of metasomatic magnesian rocks, in metamorphic rocks of medium to strong gradient (gneiss, amphibolite, metaquartzite, granulite) and more rarely in schistous formations derived from clayey sediments or basic to ultrabasic magmatic rock (peridotites, serpentines, etc...). Its name comes from the Latin anthophyllum (clove), due to its brown color. It generally occurs in fibrous, asbestiform masses, reaching 25 cm, then called amosite but also qualified as brown asbestos. It rarely occurs in crystals in the form of orthorhombic prisms, of a brownish-green to brownish-grey and brown color. It is commonly polished and used as an ornamental or jewelry stone, while in the form of asbestos it was used as a fireproof material, thermal and electrical insulation panels, etc...

Anthophyllite in the World

The most classic anthophyllite localities are Kongsberg (Norway), Dürrenstein (Austria), Kangerluarsuk (Greenland), Hermanov (Czech Republic), and the Wakefield pegmatite (Quebec) which yielded long prismatic crystals. Asbestiform anthophyllite is known in several localities in the USA : Kamia (Idaho), Sall Mount (Georgia) and Carrville (California) as well as in South Africa.

Photo on the right : anthophyllite from Paakkila Mine, Finland © Jyirki Autio

Anthophyllite in France

In France, anthophyllite is found in attractive fibrous masses at Allevier (Haute-Loire) in a serpentinized peridotite, but also in the former talc quarry of Séchier (Hautes-Alpes).

Twinning

No known twins for this mineral species.

Fakes and treatments

No fake recorded for this mineral species, but often confused with astrophyllite (much rarer) on the mineral market.



Hardness :  5.5 to 6
Density : 2.85 to 3.37
Fracture : Conchoidal
Trace : White to gray




TP : Translucent to transparent
RI : 1.598 to 1.697
Birefringence : 0.017 to 0.023
Optical character : Biaxial +
Pleochroism : Visible
Fluorescence : None


Solubility : Hydrofluoric acid

Magnetism : Paramagnetic
Radioactivity : None

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/