Dumortierite Quartz

Physical Properties

Hardness: 7 (Mohs), Color: Dark blue to violet-blue with denim-like patches, Luster: Vitreous to dull, Crystal Structure: Orthorhombic (as inclusions), Specific Gravity: 3.2-3.4

Formation & Geological History

Formed in regional metamorphic rocks rich in aluminum, such as gneiss and schist, often found in pegmatites through hydrothermal alteration processes.

Uses & Applications

Used primarily for semi-precious jewelry, ornamental carvings, and high-quality porcelain ceramics due to its refractory properties.

Geological Facts

It was named after the French paleontologist Eugene Dumortier. It is often mistaken for Sodalite or Lapis Lazuli but is significantly harder.

Field Identification & Locations

Identify by its characteristic 'denim' blue color and superior hardness compared to other blue stones. Found in Brazil, Madagascar, and the USA.

Identified on: 5/5/2026

Mode: Standard