how to facet
gemstone main cabochon creation
mineral data to quartz overview
Mineral Name: quartz
Gem Names: aventrine
Chemistry: SiO2
Class: silicate - cryptocrystalline
Crystal Sys: crypocrystalline
Hardness: 6.0 - 7.0 Specific Gravity: 2.64 - 2.69
Fracture: uneven to conchodial Refractive Index: 1.54 - 1.55
Dispersion: none
Misc Prop: Aventurine is more of a rock than a mineral. It is a metamorphised sandstone with a multitude of tiny encapsulated secondary minerals depending on the color. In the case of green aventurine the encapsulated material is the mica, fuchsite.

There is also a warm orange color of aventurine that has entrapped hematite leaves in the structure. It has, in a since been made synthetically. Although not a true synthetic chemical equivalent, it has been simulated with a variant of glass called goldstone. (See synthetics elsewhere in these pages.)

Color: In gemstones, color, is often the key to naming or describing the particular variety. Hence look for this information below in the various descriptions. Color, opacity, and homogeneity often determine the placement of value on any given stone, and are all optical properties of the particular stone.
Specific Data:
2 oval cabochons
2 elongated oval cabochons