gemstone

Blue lace agate (likely chalcedony)

Microcrystalline quartz, SiO₂; likely pale blue chalcedony, possibly dyed

AI-generated identification · may be incorrect

Mohs hardness 6.5–7; translucent milky blue to cream, vitreous-to-waxy luster, cryptocrystalline quartz with no visible cleavage and conchoidal fracture. The smooth domed surface indicates a polished cabochon or tumbled stone.

Identified September 17, 2026More gemstone →

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Physical properties

Formation & geological history

Forms when silica-rich groundwater fills cavities in volcanic rocks, commonly as layered chalcedony; deposits are mainly Cenozoic to Mesozoic in age. Fine blue color may be natural or enhanced by dyeing.

Uses & applications

Used for cabochons, beads, carvings, and ornamental objects; durable enough for jewelry but less valuable than fine transparent gemstones.

Geological facts

Blue lace agate is prized for delicate banding, though this specimen appears unusually uniform and may be common blue chalcedony or treated agate.

Field identification & locations

Identify by its waxy luster, translucency, quartz hardness, and absence of cleavage; genuine agate often shows curved or parallel banding under strong light. Common sources include Namibia, South Africa, Brazil, Uruguay, and Mexico.