mineral

Blue Quartz (Dumortierite Quartz)

Silicon Dioxide (SiO2) with inclusions of Dumortierite (Al7BO3(SiO4)3O3)

Hardness: 7.0 on Mohs scale; Color: Denim blue, violet-blue, or indigo; Luster: Vitreous to waxy; Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.62-2.67

Hardness: 7
Color: Denim blue, violet-blue, or indigo
Luster: Vitreous to waxy

Identified July 19, 2026More mineral →

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Physical properties

Formation & geological history

Formed in silica-rich pegmatites or metamorphic environments where alumina-rich sediments were subjected to high-grade metamorphism. The blue color is derived from fibrous inclusions of the mineral dumortierite.

Uses & applications

Used primarily for ornamental purposes, jewelry (beads, cabochons), metaphysical collecting, and as a pocket stone/tumbled stone.

Geological facts

Unlike Sapphire or Blue Lace Agate, the blue in this quartz is caused by inclusions of another mineral rather than trace chemical elements. It was named after the French paleontologist Eugne Dumortier.

Field identification & locations

Identify by its denim-blue hue and typical quartz hardness (cannot be scratched by steel). It is commonly found in Brazil, Namibia, Madagascar, and the USA. Collectors should look for the characteristic fibrous patterns within the stone.

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