Tumbled jasper

Typically Mohs hardness 6.5–7, opaque, reddish-brown to mustard-brown, with a waxy to glassy luster and no visible cleavage; the rounded shape indicates tumbling and polishing.

Jasper forms when silica-rich groundwater fills cavities or replaces volcanic or sedimentary material, with iron producing the brown-red coloration. Most specimens formed in ancient volcanic or sedimentary environments, commonly over millions of years.

Used for ornamental objects, cabochons, beads, carvings, and inexpensive lapidary material; polished pieces are popular among collectors.

Jasper is a variety of opaque chalcedony or microcrystalline quartz, not a single mineral species. Color and patterns depend strongly on iron, manganese, clay, and other inclusions.

Identify it by its opaque earthy color, fine-grained texture, quartz-like hardness, and inability to scratch with a steel knife easily; common sources include India, Madagascar, Brazil, Australia, and the western United States. A definitive identification may require hardness, streak, or microscopic testing.