gemstone

Blue chalcedony crystal pendant

Chalcedony, microcrystalline quartz (SiO₂), likely blue chalcedony or dyed quartz

AI-generated identification · may be incorrect

Mohs hardness 6.5–7; translucent pale blue, waxy to vitreous luster, cryptocrystalline structure, and no visible cleavage. The elongated polished point and metal cap indicate a cut and mounted specimen.

Identified August 23, 2026More gemstone →

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Physical properties

Formation & geological history

Chalcedony forms when silica-rich groundwater fills cavities and fractures, commonly in volcanic rocks; formation ages range from recent to Precambrian. The blue color may be natural, caused by inclusions or dispersed minerals, or enhanced by dyeing.

Uses & applications

Used for pendants, beads, carvings, and ornamental objects. Common material has modest jewelry value, while vivid natural blue chalcedony is more desirable.

Geological facts

Chalcedony is a variety of quartz composed mainly of intergrown quartz and moganite. Its smooth waxy appearance and even color distinguish it from coarse crystalline quartz.

Field identification & locations

Commonly found in volcanic cavities and silica-rich veins, including Brazil, Turkey, India, Madagascar, and the United States. A glassy look, bubbles, or uniform artificial color may suggest glass or dye; hardness testing can help distinguish it.