Aventurine is a form of quartz, characterized by its translucency and the presence of platy mineral inclusions that give a shimmering or glistening effect termed aventurescence. The most common color of aventurine is green, but it may also be orange, brown, yellow, blue, or grey. Aventurine is between 6.5 to 7 on the Mohs hardness scale.  Aventurine is thought to calm and relax, help with nervousness, stress and sleep disorders.