mineral

Blue quartz (likely dumortierite-in-quartz)

Quartz, SiO₂, colored by fibrous dumortierite inclusions

AI-generated identification · may be incorrect

Hardness ~7 Mohs; blue-gray to violet-blue, translucent to opaque, with a vitreous luster and irregular fracture. Crystal structure is trigonal quartz; cleavage is absent, and specific gravity is ~2.65.

Identified September 7, 2026More mineral →

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Physical properties

Formation & geological history

Forms when quartz crystallizes in metamorphic or hydrothermal environments containing aluminum-rich fluids, commonly during Precambrian to younger mountain-building events. The photograph alone cannot confirm the inclusions or exact variety.

Uses & applications

Used mainly as a collector specimen, cabochon, or ornamental stone; attractive pieces may be sold as “blue quartz.” It has little industrial value compared with ordinary quartz.

Geological facts

Blue quartz is uncommon and its color may result from dumortierite, crocidolite, rutile, or other microscopic inclusions. It should not be confused with dyed quartz, blue glass, or blue apatite.

Field identification & locations

Look for a glassy luster, hardness that scratches ordinary glass, no cleavage, and blue color distributed through quartz rather than a metallic surface. Common sources include Brazil, Madagascar, the United States, and Norway.