Green Aventurine

Hardness: 6.5-7.0 (Mohs scale), Color: Dull green to dark green, Luster: Vitreous to waxy, Crystal Structure: Trigonal (microcrystalline), Cleavage: None, Specific Gravity: 2.64-2.69

Formed through the regional metamorphism of sandstone into quartzite, where interstitial mineral inclusions (typically green Fuchsite mica) are trapped during recrystallization. These specimens can range from Precambrian to more recent geological ages.

Primarily used for lapidary work including cabochons, beads, and carvings. Also used in ornamental construction, such as aquarium decor, and widely sold in the metaphysical/collecting market.

The name comes from the Italian 'a ventura' (by chance), referring to the 18th-century accidental discovery of 'aventurine glass'. Natural aventurine is known for 'aventurescence', a glittering effect caused by light reflecting off tiny platy mineral inclusions.

Identify by its characteristic 'shimmer' or grainy appearance under light, distinct from the solid color of jade. Commonly found in India, Brazil, and Russia. Collectors look for uniform color and strong aventurescence.