Cause of Color :
Aventurescent effect due to reflections from metallic inclusion like hematite, goethite or copper.
Chemical Composition :
Aluminum silicate of potassium, sodium and calcium. KAlSi3O8. Isomorphous series made up of Albite (Na), Oligoclase, Andesine, Labradorite, Bytownite and Anorthite (Ca) where the two end member are NaAlSi3O8 and CaAl2Si2O8.
Crystal System / Forms :
Cuts & Uses :
Facetted, cabochon, beads and carving.
Platelets of goethite, copper, hematite, fingerprints and crystal inclusions.
Optic Character :
Anisotropic, D.R.; Biaxial negative
Refractive Index / Birefringence :
1.542 – 1.549 / 0.00
Simulants (with separation tests) :
Sunstone simulated by aventurine quartz (structure), goldstone glass (inclusions).
U.S.A. (Oregon), India, Kenya, Norway, Russia.