Amazonite - Encyclopedia

    Class : Silicates
    Subclass : Tectosilicates
    Crystal System : Triclinic
    Chemistry : KAlSi3O8
    Rarity : Rare

Amazonite is a blue-green to green microcline variety, a potassic feldspar. The green color is due to a replacement in the crystal structure of 2 atoms of potassium by a lead atom. A single atom instead of 2 : this replacement causes a sudden vacuum (or vacant site) in the crystal structure called "color center". This vacuum passes a wavelength corresponding to the green color and the mineral does not absorb it then appears green. Amazonite is the richest lead feldspar (sometimes up to 1.2%). It owes its name to the Amazon River where it was discovered. It is only found in granitic pegmatites. Its green aesthetic color is worthy of significant use in ornamentation and jewelry, where it is frequently cut in cabochon while its crystals are sought after by mineral collectors.

Smoky quartz and amazonite from Crystal Peak Area, Colorado, USA
47.75 ct amazonite from Brazil
33.61 ct amazonite from Brazil
29,00 ct amazonite from Brazil

Amazonite in the World :

Superb crystallized samples of amazonite have been found at several sites. Crystal Peak and Pike's Peak (Colorado) provided extraordinary crystals exceeding 25 cm, commonly twinned (twin Baveno and Manebach) and associated with beautiful smoky quartz and sometimes brown topaz. Beautiful crystals, sometimes of significant size, were also extracted from the pegmatites of Amelia (Virginia) and the provinces of Laghman and Kunar (Afghanistan). Huge metrical crystals of amazonite, with very clean faces were discovered in the 70's in a pegmatite of the region of Itabira, on the banks of the Rio Doce (Minas Gerais, Brazil) : one of them , perfectly formed and weighing 500 kg is kept at the Paris Museum. Magnificent decimetric crystals also come from the Ilmen Mountains in the Southern Urals, Madagascar, India and Mozambique.

Amazonite in France :

In France, amazonite was described in the 70's in a porphyritic granite in Corsica in Vizzavona.

Fakes and treatments :

No fake invented for this stone.



Hardness : 6 to 6.5
Density : 2.54 to 2.57
Fracture : Uneven to conchoidal

Streak : White



TP : Translucent to opaque
IR : 1.514 to 1.539
Birefringence : 0.007 to 0.010
Optical character : Biaxial -
Pleochroism : Variable
Fluorescence : Green-yellow


Solubility : Hydrofluoric acid

Magnetism : None
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

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/