gemstone

Yellow chalcedony (likely dyed or heat-treated)

Microcrystalline quartz, SiO₂ (chalcedony)

AI-generated identification · may be incorrect

Translucent golden-yellow, waxy to vitreous luster, cryptocrystalline structure, no visible cleavage, Mohs hardness about 6.5–7, specific gravity approximately 2.60. Its smooth rounded form indicates tumbling or cabochon polishing.

Identified September 5, 2026More gemstone →

Explore Yellow chalcedony (likely dyed or heat-treated) in the encyclopedia →

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Physical properties

Formation & geological history

Chalcedony forms when silica-rich fluids fill cavities and fractures, commonly in volcanic rocks; yellow color may be natural iron staining or treatment. Precise geological age cannot be determined from the image.

Uses & applications

Used for cabochons, beads, carvings, and inexpensive jewelry; quality depends on color, translucency, and absence of cracks.

Geological facts

It may be marketed as yellow agate, lemon quartz, or “golden chalcedony,” though those names are not always mineralogically precise.

Field identification & locations

Common sources include Brazil, Uruguay, India, Madagascar, and the western United States. Identify by its waxy appearance, lack of cleavage, hardness sufficient to scratch glass, and absence of bubbles; bubbles would suggest glass.