mineral

Polished jasper/chalcedony pebble

Microcrystalline quartz (SiO₂), likely brecciated or iron-stained jasper

AI-generated identification · may be incorrect

Hardness about 6.5–7 Mohs; opaque to slightly translucent brown, tan, red, and gray, with a waxy to dull luster. It has cryptocrystalline quartz structure, no obvious cleavage, and typical specific gravity near 2.6.

Identified August 12, 2026More mineral →

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Physical properties

Formation & geological history

Silica-rich groundwater deposited chalcedony and quartz in cavities or fractures, while iron oxides produced the red-brown coloration; brecciation may account for the contrasting band. Such material commonly formed in volcanic or sedimentary settings over millions of years.

Uses & applications

Used for cabochons, beads, carvings, decorative stones, and lapidary practice; occasional pieces are sold as jasper or scenic agate.

Geological facts

The specimen appears naturally rounded and polished/tumbled, so surface texture and true field relationships are obscured. Its translucency and waxy appearance favor chalcedony-rich jasper over ordinary brown quartzite.

Field identification & locations

Identify by its glassy-to-waxy hardness, lack of cleavage, fine texture, and inability to scratch it with a steel knife easily; quartz will scratch glass. Common sources include volcanic terrains and gravel deposits worldwide.