mineral

Orbicular jasper (polished jasper slab)

Orbicular jasper; microcrystalline quartz/chalcedony (SiO₂) with iron-oxide and other mineral inclusions

AI-generated identification · may be incorrect

Hardness about 6.5–7 Mohs; opaque, waxy to dull luster, with cream, gray-green, salmon-red, and brown concentric orbicules. It has a cryptocrystalline quartz structure and no obvious cleavage; density is typically about 2.5–2.7.

Identified August 13, 2026More mineral →

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At a glance

Common name: Orbicular jasper (polished jasper slab)
Scientific name: Orbicular jasper; microcrystalline quartz/chalcedony (SiO₂) with iron-oxide and other mineral inclusions
Category: mineral
Identified: August 13, 2026
Method: Standard

AI Estimated Value

Approximately $10–$50 for a small polished specimen; $50–$200+ for large, vividly patterned slabs or fine cabochons.

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

Formation & geological history

Forms when silica-rich volcanic or hydrothermal fluids replace or cement volcanic rock, producing radiating/concentric mineral aggregates; iron oxides create the red coloration. Specific age depends on locality, commonly Paleozoic to Cenozoic.

Uses & applications

Used for cabochons, beads, carvings, decorative slabs, and lapidary displays; attractive patterns give quality pieces modest collector value.

Geological facts

The orbicules are mineral-rich growth zones, not fossils; patterns vary greatly even within one deposit.

Field identification & locations

Identify by testing for quartz-like hardness, opaque fine-grained texture, and natural concentric orbs in a silicified matrix. Similar material occurs in Madagascar, Mexico, Australia, Indonesia, and the western United States.