gemstone

Polished blue chalcedony (likely blue quartz/chalcedony)

Microcrystalline quartz, SiO₂; blue color commonly from inclusions or coloration

AI-generated identification · may be incorrect

Pale blue, translucent-to-opaque, waxy-to-glassy luster, rounded polished surface; Mohs hardness 6.5–7, no cleavage, conchoidal fracture, trigonal quartz structure, specific gravity about 2.6.

Identified August 11, 2026More gemstone →

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At a glance

Common name: Polished blue chalcedony (likely blue quartz/chalcedony)
Scientific name: Microcrystalline quartz, SiO₂; blue color commonly from inclusions or coloration
Category: gemstone
Identified: August 11, 2026
Method: Standard

AI Estimated Value

About $5–$30 for a small polished common piece; $50–$200+ for unusually natural, vivid, translucent, or provenance-documented material.

Not an official valuation

AI estimate for general interest only — not an appraisal. Actual value depends on condition, provenance, and market demand. Verify with a professional before buying, selling, or insuring.

This identification was generated by AI and may contain errors. Verify important details before relying on them — and never use an AI result to judge whether a specimen is safe to handle. Read the full disclaimer

Physical properties

Pale blue, translucent-to-opaque, waxy-to-glassy luster, rounded polished surface; Mohs hardness 6.5–7, no cleavage, conchoidal fracture, trigonal quartz structure, specific gravity about 2.6.

Formation & geological history

Forms when silica-rich groundwater fills cavities and fractures, precipitating microscopic quartz fibers; commonly Cenozoic to older volcanic-hosted material. The pictured piece is polished, so natural texture and locality are obscured.

Uses & applications

Used for cabochons, beads, carvings, ornaments, and inexpensive collector specimens; suitable for jewelry but less valuable than fine blue lace agate or gem-quality blue chalcedony.

Geological facts

Blue chalcedony is often confused with dyed quartz, glass, or blue calcite; uniform intense color may indicate treatment. It does not fizz in dilute hydrochloric acid.

Field identification & locations

Common sources include Indonesia, Turkey, Namibia, Brazil, Madagascar, and the United States. Confirm with hardness, magnification, refractive index, and specific gravity; avoid relying on color alone.