Blue Quartz (Aventurine)

Physical Properties

Hardness: 7 (Mohs); Color: Denim blue to dark blue; Luster: Vitreous to waxy; Crystal structure: Hexagonal/Trigonal; Cleavage: None/Conchoidal fracture; Specific gravity: 2.63 - 2.65

Formation & Geological History

Formed through the heating and cooling of magma or by precipitation from hydrothermal fluids in veins. The blue color is typically caused by inclusions of fibrous blue minerals like dumortierite or crocidolite during the growth process.

Uses & Applications

Primarily used as a gemstone for jewelry, ornamental carvings, tumbling, and in the metaphysical/collecting community.

Geological Facts

Unlike Lapis Lazuli, which is a rock made of several minerals (including lazurite), blue quartz is a single mineral variety. Its color is often described as 'denim-like' due to the micro-inclusions scattered throughout the quartz matrix.

Field Identification & Locations

Identify in the field by its hardness (will scratch glass), lack of cleavage, and common association with metamorphic or hydrothermal environments. It is frequently found in Brazil, India, and South Africa.

Identified on: 4/25/2026

Mode: Standard