Blue Aventurine
Quartzite with Dumortierite inclusions (SiO2 + Al7(BO3)(SiO4)3O3)
Rock Type: metamorphic

Physical Properties
Hardness: 7 (Mohs scale), Color: Silvery-blue to dark indigo, Luster: Vitreous to waxy, Crystal Structure: Hexagonal (trigonal), Cleavage: None, Specific Gravity: 2.63–2.69
Formation & Geological History
Formed through the regional metamorphism of quartz-rich sandstone where dumortierite inclusions are present, giving it the characteristic blue color and aventurescence.
Uses & Applications
Primarily used for lapidary work, jewelry, decorative carvings, palm stones, and metaphysical purposes/collecting.
Geological Facts
The shimmering effect seen in aventurine is called 'aventurescence,' caused by tiny mineral inclusions that reflect light. While green aventurine is common (mica inclusions), blue is rarer and gets its color from dumortierite crystals.
Field Identification & Locations
Identify by its grainy quartzite texture combined with a distinct blue hue and subtle sparkle. Commonly found in Brazil, India, and parts of Russia. Collectors should look for even color distribution and a lack of dye, which is common in cheaper imitations.
Identified on: 4/29/2026
Mode: Standard