mineral

Blue Chalcedony

Silicon Dioxide (SiO2)

Hardness of 6.5 to 7 on the Mohs scale, color ranges from pale blue to greyish-blue, waxy to vitreous luster, cryptocrystalline crystal structure, no cleavage, specific gravity of 2.58 to 2.64.

Identified August 4, 2026More mineral →

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Physical properties

Hardness of 6.5 to 7 on the Mohs scale, color ranges from pale blue to greyish-blue, waxy to vitreous luster, cryptocrystalline crystal structure, no cleavage, specific gravity of 2.58 to 2.64.

Formation & geological history

Formed in low-temperature hydrothermal veins, volcanic cavities, and sedimentary environments by the deposition of silica-rich groundwater.

Uses & applications

Used in ornamental carvings, gemstone jewelry, tumbled stones, and spiritual or metaphysical practices.

Geological facts

Chalcedony has been used since antiquity for intaglios, seals, and beads. The blue variety is particularly soothing and often associated with calm communication.

Field identification & locations

Can be identified by its smooth waxy feel, subtle translucent banding or uniform soft blue color, and conchoidal fracture. Commonly found in locations like Brazil, India, Madagascar, and the USA.