Aventurine

Aventurine is a form of quartzite, characterised by its translucency and the presence of platy mineral inclusions that give it a shimmering or glistening effect termed aventurescence.

Chrome-bearing fuchsite (a variety of muscovite mica) is the classic inclusion and gives a silvery green or blue sheen.

Because aventurine is a rock, its physical properties vary: its specific gravity may lie between 2.64–2.69 and its hardness is somewhat lower than single-crystal quartz at around 6.5.

One story is that this kind of glass was originally made accidentally at Murano by a workman, who let some copper filings fall into the molten "metal", whence the product was called avventurino.

[citation needed] The majority of green and blue-green aventurine originates in India (particularly in the vicinity of Mysore and Chennai) where it is employed by prolific artisans.