mineral

Polished/tumbled brown stone, likely brown jasper or chert

Microcrystalline quartz (SiO₂), probably jasper/chert; exact identification requires testing

AI-generated identification · may be incorrect

Opaque orange-brown, smooth tumbled surface, dull to slightly waxy luster, no visible cleavage, and likely Mohs hardness about 6.5–7. Specific gravity is approximately 2.6–2.7.

Identified September 11, 2026More mineral →

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At a glance

Common name: Polished/tumbled brown stone, likely brown jasper or chert
Scientific name: Microcrystalline quartz (SiO₂), probably jasper/chert; exact identification requires testing
Category: mineral
Identified: September 11, 2026
Method: Standard

AI Estimated Value

About $2–$15 for a common tumbled piece; roughly $10–$50 if unusually attractive, patterned, or sold as quality jasper.

Not an official valuation

AI estimate for general interest only — not an appraisal. Actual value depends on condition, provenance, and market demand. Verify with a professional before buying, selling, or insuring.

This identification was generated by AI and may contain errors. Verify important details before relying on them — and never use an AI result to judge whether a specimen is safe to handle. Read the full disclaimer

Physical properties

Opaque orange-brown, smooth tumbled surface, dull to slightly waxy luster, no visible cleavage, and likely Mohs hardness about 6.5–7. Specific gravity is approximately 2.6–2.7.

Formation & geological history

Formed from silica-rich fluids or sediment producing microcrystalline quartz, commonly with iron-oxide coloration. The natural material may be Paleozoic or younger; tumbling is human processing and obscures original texture.

Uses & applications

Used as a lapidary stone, cabochon, ornament, paperweight, or inexpensive collectible; occasionally used for beads and small carvings.

Geological facts

Jasper and chert are varieties of cryptocrystalline quartz and can look nearly identical when polished. The reddish-brown color commonly comes from hematite or limonite inclusions.

Field identification & locations

Look for glassy fracture, absence of cleavage, and inability to scratch it with a steel knife; it should scratch window glass, though testing a polished specimen may damage it. Common sources include India, Madagascar, Brazil, the United States, and Mexico.