gemstone

Yellow chalcedony (likely agate) cabochons

Microcrystalline quartz, SiO₂; chalcedony variety, possibly naturally colored or dyed

AI-generated identification · may be incorrect

Translucent honey-yellow, polished cabochons with a waxy-to-glassy luster; quartz hardness 6.5–7, trigonal crystal structure at the microscopic level, no cleavage. The photo cannot establish whether the color is natural or treated.

Identified October 3, 2026More gemstone →

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Physical properties

Formation & geological history

Forms as silica-rich fluids deposit cryptocrystalline quartz in cavities and fractures, commonly in volcanic rocks; agate may show banding. Chalcedony deposits span many geological ages.

Uses & applications

Used in cabochon jewelry, beads, and decorative objects; value depends on color, pattern, size, and treatment.

Geological facts

Chalcedony is made of intergrown microscopic quartz crystals and may appear uniformly colored or banded.

Field identification & locations

Look for waxy luster, translucency, and hardness; agate often has curved or concentric bands. Common sources include Brazil, Uruguay, India, and Madagascar; these appear to be small polished stones.