Orange Aventurine

India is by far the most important commercial producer of aventurine and Brazil is second; smaller amounts come from Russia, Spain, Austria and Tanzania. Aventurine is a variety of quartzite, a metamorphic rock formed when quartz sandstone or chert recrystallizes into a tight network of quartz grains. Reddish-orange aventurine rough is among the colours exported from India for tumbling.

Magnification with darkfield lighting shows the small colour-causing inclusions. Hematite, ilmenite and goethite are denser than quartz, so heavily included pieces can have a specific gravity above that of quartz. Translucent quartz with little or no aventurescence is often dyed bright colours and sold as "aventurine"; dye concentrations can be seen with magnification, and unusually vivid colours call for caution. Goldstone (aventurine glass) is distinguished by its much lower hardness and by its uniform copper crystals, whose shape can readily be made out with a lens.

Aventurine has the hardness of quartz (6.5 to 7), but abundant mica can lower its apparent hardness and give it a direction of easier breakage, and coarse mica flakes can pluck out of a polished surface and leave pits. IGS lists no special care for quartz, but notes that some dyes used on quartz fade, which matters for the oiled or dyed beads that are common in the trade.

Mindat derives the name from the Italian "a ventura", meaning "by chance", and links it to aventurine glass, a glittering glass with copper inclusions first made in Italy. Mindat also notes that "aventurine" is used commercially for several kinds of stones, including aventurine feldspar (sunstone); the natural quartz material is also called aventurine quartz and is not to be confused with aventurine glass (goldstone).

The Japanese retailer Pascle writes that orange aventurine, like green aventurine, is said to ease stress and tension, and that because its bright colour recalls ripe fruit it is said to help love "bear fruit".