mineral

Polished yellow chalcedony (likely lemon agate or yellow jasper)

Microcrystalline quartz, SiO₂

AI-generated identification · may be incorrect

Hardness about 6.5–7 Mohs; opaque to slightly translucent, creamy yellow with orange-brown internal wisps and a waxy-to-glassy polish. Quartz has no cleavage and a cryptocrystalline structure; specific gravity is about 2.6.

Identified August 18, 2026More mineral →

Explore Polished yellow chalcedony (likely lemon agate or yellow jasper) in the encyclopedia →

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Physical properties

Formation & geological history

Forms when silica-rich groundwater fills cavities or fractures, with iron impurities producing yellow-orange coloration; typically Cenozoic to older volcanic or sedimentary-hosted material. The rounded shape indicates tumbling or carving.

Uses & applications

Used for lapidary carvings, cabochons, beads, ornaments, and inexpensive jewelry. It is also collected as a decorative quartz variety.

Geological facts

The image cannot reliably distinguish yellow chalcedony from yellow jasper; visible translucency and lack of granular texture favor chalcedony. A steel file should not scratch it, while quartz should scratch glass.

Field identification & locations

Common sources include Brazil, Madagascar, India, Uruguay, and the western United States. Look for uniform cryptocrystalline texture, waxy luster, conchoidal fracture, and iron staining rather than visible grains.