gemstone

Blue chalcedony (likely dyed or treated)

Microcrystalline quartz, SiO₂ (chalcedony)

AI-generated identification · may be incorrect

Hardness 6.5–7 Mohs; translucent pale blue with waxy-to-vitreous luster and conchoidal fracture, commonly polished into beads. The spherical beads and uniform color suggest commercial treatment or possible opalite imitation; crystal structure is cryptocrystalline quartz.

Identified August 27, 2026More gemstone →

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Physical properties

Formation & geological history

Chalcedony forms when silica-rich groundwater fills cavities and fractures, usually in volcanic rocks, through low-temperature precipitation. Deposits occur in many geologic ages; blue material is notably associated with Namibia, Turkey, Indonesia, and the United States.

Uses & applications

Used for beads, cabochons, carvings, and ornamental objects; durable enough for jewelry. Common polished beads generally have modest value.

Geological facts

Natural blue chalcedony is typically subtler and more variable than these beads; vivid, evenly translucent blue specimens may be dyed. Opalite, a man-made glass, can look similar but is softer and usually shows stronger internal glow.

Field identification & locations

Check for tiny dye concentrations in pits or drill holes, test hardness only on an inconspicuous area, and use refractive index or gemological testing to separate chalcedony from glass. Typical value is about $5–$30 for the strand shown, or $20–$100 for fine natural blue chalcedony beads.