Aventurine

Aventurine is a compact variety of Quartz / Chalcedony containing small included flakes or scales that give it a glistening effect. The inclusions are usually Muscovite mica, but may also be Hematite or Goethite. Though the color of Aventurine is most often associated with green, it can also be other colors such as gray, orange, and brown. However, color types other than green are uncommon, and rarely used as gemstones or ornamental material.
Chemical Formula SiO2
Color Blue, Green, Yellow, Orange, Brown, Gray
Hardness 6.5Â -Â 7
Crystal System Hexagonal
Refractive Index 1.54Â -Â 1.55
SG 2.63Â -Â 2.65
Transparency Opaque. May be translucent when backlit on the edges.
Double Refraction .009
Luster Vitreous, waxy
Cleavage Indiscernible
Mineral Class Quartz / Chalcedony