gemstone

Tumbled jasper

Microcrystalline quartz (chalcedony), SiO₂; likely iron-stained jasper

AI-generated identification · may be incorrect

Opaque, mottled cream, tan, and reddish brown with a waxy to vitreous polish; quartz’s trigonal crystal structure is microscopic, with no visible cleavage. Hardness is about 6.5–7 Mohs and specific gravity about 2.6.

Identified October 11, 2026More gemstone →

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Physical properties

Formation & geological history

Silica-rich fluids or sediment can form microcrystalline quartz, with iron oxides producing the brown-red colors; the pebble has been mechanically tumbled and polished. The exact source and geological age cannot be determined from the image.

Uses & applications

Used for inexpensive jewelry, beads, ornaments, and lapidary collecting; jasper has also been carved into decorative objects.

Geological facts

Jasper is an opaque variety of chalcedony, distinguished from many agates by its opacity and abundant impurities.

Field identification & locations

The smooth, rounded shape and polish indicate a processed pebble; jasper commonly occurs in silica-rich veins and sedimentary settings worldwide. A scratch test on an inconspicuous spot can help distinguish quartz-rich jasper from softer imitations.