Green Aventurine
Quartz var. Aventurine · Semi-Precious Gemstone / Decorative Stone
Crystal System
Trigonal; commonly occurs in massive or granular habits rather than distinct crystals.
Mineral Group
Silicates (Tectosilicate subgroup; Quartz group)
Chemical Formula
SiO2 (Silicon Dioxide) with inclusions of Fuchsite (K(Al,Cr)2(AlSi3O10)(OH)2)
Formation Process
Metamorphic or Magmatic; forms through the crystallization of silica-rich fluids where plate-like inclusions like mica are present and become trapped during cooling.
About This Crystal
A translucent to opaque green variety of quartz characterized by a 'shimmery' or 'glittery' appearance known as aventurescence. This specimen is a rounded, tumbled stone with a vitreous to waxy luster and a medium-green hue.
Physical Characteristics
Color: Pale to dark green; Streak: White; Cleavage: None; Fracture: Conchoidal to splintery; Specific Gravity: 2.64–2.69; Fluorescence: Generally inert, but may show weak reddish-white under UV if certain inclusions are present.
Optical Properties
Refractive Index: 1.544–1.553; Birefringence: 0.009; Optical Phenomena: Aventurescence caused by light reflecting off tiny platy inclusions of green Fuchsite mica.
Hardness & Durability
Origin Region
India (primary source), Brazil, Russia, and Tanzania; typically found in metamorphic rocks and magmatic pegmatites.
Hardness & Durability
Mohs Hardness: 6.5–7; Toughness: Good (due to its granular structure); Stability: Stable under normal light and heat, though extreme heat may alter color.
Care & Maintenance
Clean with warm soapy water and a soft cloth; safe for ultrasonic cleaners generally. Store away from harder stones like Topaz or Sapphire to prevent scratching.
Rarity & Value
Common; very affordable. Value depends on the intensity of the green color and the quality of the aventurescence (the 'sparkle' factor). Often sold as tumbled stones or carvings.
Special Characteristics
Aventurescence: An optical shimmering effect caused by the reflection of light from tiny platy inclusions within the quartz. It may also contain hematite or goethite in reddish varieties.
Lore & History
Historically used in Ethiopia as early as the 18th century for tools; traditionally known as the 'Stone of Opportunity' in folk lore. In modern crystal healing, it is associated with the Heart Chakra and believed to promote prosperity and emotional calm.