mineral

Dumortierite Quartz (Blue Quartz)

Al7BO3(SiO4)3O3 (Aluminum Boro-silicate included in Quartz)

Hardness: 7.0 (Mohs scale), Color: Sky blue to dark violet-blue with white/gray inclusions, Luster: Vitreous to waxy, Crystal Structure: Orthorhombic (as inclusions in Hexagonal quartz), Cleavage: Indistinct, Specific Gravity: 3.26–3.41

Hardness: 7

Identified March 25, 2026More mineral →

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Physical properties

Formation & geological history

Formed in aluminum-rich regional metamorphic environments, often found in pegmatites or high-temperature hydrothermal systems. Frequently occurs as fibrous inclusions within quartz crystals.

Uses & applications

Used primarily for ornamental carvings, cabochons for jewelry, and as a collector's gemstone. Industrially, it is used in the manufacturing of high-grade porcelain and ceramics due to its high aluminum content.

Geological facts

Many people mistake it for Sodalite or Lapis Lazuli, but it is much harder and lacks the pyrite inclusions of Lapis. It was named after the French paleontologist Eugène Dumortier in 1881.

Field identification & locations

Identify by its hardness (it should easily scratch glass) and its fibrous, denim-blue appearance. Commonly found in Madagascar, Brazil, and Namibia. In the field, look for matte, fibrous blue veins in metamorphic rock outcrops.

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