Aventurine is a form of quartz that is given visual distinction by its unique, shimmering surface- a certain metallic glisten that is caused by the inclusion of minerals on the surface of the quartz in final formative stages. Depending on the mineral that bonds to the stone's surface, different reflective effects are achieved, and different colours are produced. For example, quartz that contains fuchsite will appear green, whereas the presence of iron oxide will create a red appearance, and dumortierite will cause it to look blue.
The remarkable glitter of aventurine has earned its own descriptor: 'aventurescent'. The word aventurescence is applied to anything that shares or approaches aventurine's distinctive sparkle.
For those interested in aventurine's healing or metaphysical properties, a division is made between different colours of the gemstone. While green aventurine is associated with good luck and assistance in leadership initiatives, blue aventurine is thought to aid insight, the cultivation of patience, and bodily detoxification.
Source: http://www.stonesandfindings.com/jewelry-making-articles/articles/aventurine
