mineral

Blue Quartz (specifically Dumortierite Quartz)

SiO2 (Silicon Dioxide) with inclusions of AlAl6BSi3O18 (Dumortierite)

Hardness: 7 on the Mohs scale. Color: Denim blue, grayish-blue, or indigo. Luster: Vitreous to dull. Crystal Structure: Hexagonal (Trigonal). Cleavage: None. Specific Gravity: 2.65 - 2.85.

Hardness: 7 on the Mohs scale
Color: Denim blue, grayish-blue, or indigo
Luster: Vitreous to dull

Identified March 14, 2026More mineral →

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Physical properties

Hardness: 7 on the Mohs scale. Color: Denim blue, grayish-blue, or indigo. Luster: Vitreous to dull. Crystal Structure: Hexagonal (Trigonal). Cleavage: None. Specific Gravity: 2.65 - 2.85.

Formation & geological history

Formed through hydrothermal processes where quartz crystallizes alongside dumortierite inclusions. It occurs in regional metamorphic rocks such as gneiss and schist, as well as some granitic pegmatites.

Uses & applications

Commonly used for lapidary work, cabochons for jewelry, decorative carvings, and as a popular specimen for crystal collectors and 'metaphysical' use.

Geological facts

Natural blue quartz is relatively rare; most 'blue quartz' on the market is either macro-crystalline quartz with dumortierite inclusions or dyed chalcedony. Unlike blue aventurine, which contains mica inclusions, the blue in this specimen comes from fibrous dumortierite.

Field identification & locations

Identify in the field by its superior hardness compared to sodalite (which is softer). It is frequently found in Brazil, Namibia, South Africa, and parts of the USA (Virginia/California). Collectors should look for the characteristic 'denim' blue color that doesn't rub off.

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