AMAZONITE
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.
Amazonite in the World :
Amazonite in France :
Fakes and treatments :
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