mineral

Polished jasper or agate pebble

Microcrystalline quartz (SiO₂), likely jasper/chalcedony; exact variety is uncertain from the photo

AI-generated identification · may be incorrect

Opaque, polished yellow, cream, and brown patterns with a waxy-to-glassy luster; quartz has Mohs hardness 7 and trigonal crystal structure, though crystals are microscopic. No visible cleavage; specific gravity about 2.6.

Identified October 12, 2026More mineral →

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Physical properties

Formation & geological history

Silica-rich fluids deposited quartz in rock cavities or replaced surrounding material, with iron oxides producing the yellow-brown colors. The specimen’s age and locality cannot be determined from the image.

Uses & applications

Commonly fashioned into cabochons, beads, and decorative objects; also collected as a polished stone.

Geological facts

Jasper and agate are varieties of chalcedony, but jasper is typically opaque while agate is often translucent or banded.

Field identification & locations

The polished surface and mottled, opaque colors fit jasper or jasper-rich chalcedony; a scratch test or locality information would help distinguish it. Chalcedony occurs worldwide in volcanic rocks and sedimentary deposits.