This structure is much more compact than the other members of the quartz group, except stishovite, and is reflected in the higher density and index of refraction. But this is a slow and complicated process taking thousands of years if it happens at all. It is a slow process mostly because the transformation involves the breaking of bonds and the rearrangement of atoms. Color is colorless or white. Luster is vitreous.
Crystals are transparent to translucent.
Cleavage information is unavailable. Fracture is probably conchoidal. Streak is clear. Refractive index is approximately 1.59 Associated Minerals include sanadine , diamond , garnets , pyroxenes , iron meteorites and stishovite . Notable Occurrences include Canyon Diablo, Meteor Crater, Arizona, USA and other meteorite craters around the world as well as at Kimberly, South Africa.