mineral

Blue chalcedony (likely dyed or polished)

Chalcedony, microcrystalline quartz (SiO₂)

AI-generated identification · may be incorrect

Hardness 6.5–7 Mohs; deep blue, translucent to opaque, with a smooth waxy-to-glassy luster and no visible cleavage. Its rounded, highly polished form is consistent with a tumbled stone; uniform intense blue may indicate dyeing.

Identified August 13, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich groundwater fills cavities and fractures, depositing microscopic quartz fibers, usually in volcanic rocks. Chalcedony occurs from relatively young to ancient geological settings worldwide.

Uses & applications

Used for cabochons, beads, carvings, ornamental objects, and lapidary specimens; it is not typically used as a major construction stone.

Geological facts

Natural blue chalcedony is uncommon; much commercial blue material is dyed gray, white, or pale chalcedony. It may be confused with blue glass, sodalite, or dyed agate.

Field identification & locations

Common sources include Turkey, Namibia, Brazil, Madagascar, India, and the United States. Check for natural variation, translucency, conchoidal fracture, and dye concentration in cracks or pores; image-only identification is provisional.