gemstone

Polished black-and-white banded agate (likely dyed or painted)

Chalcedony (microcrystalline quartz), SiO₂; exact banding variety uncertain

AI-generated identification · may be incorrect

Hardness about 6.5–7 Mohs; vitreous to waxy luster, opaque black and white bands, cryptocrystalline quartz, no visible cleavage, specific gravity about 2.60–2.65. The regular high-contrast pattern and polish suggest human processing; it may be a carved bead or pendant component.

Identified September 10, 2026More gemstone →

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At a glance

Common name: Polished black-and-white banded agate (likely dyed or painted)
Scientific name: Chalcedony (microcrystalline quartz), SiO₂; exact banding variety uncertain
Category: gemstone
Identified: September 10, 2026
Method: Standard

AI Estimated Value

About $5–$30 as a small processed bead or common specimen; up to roughly $50–$100 if confirmed natural, well-crafted, and attractive.

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

Agate forms when silica-rich groundwater fills cavities in volcanic rocks, commonly during the Paleozoic–Cenozoic; individual specimen age and locality cannot be determined from the image.

Uses & applications

Used for beads, ornaments, cabochons, and carvings; generally decorative rather than high-value jewelry material.

Geological facts

Black coloration may result from natural manganese/iron compounds, dye, or surface paint. The adjacent brown object appears separate and is not identified here.

Field identification & locations

Look for curved/concentric banding, waxy luster, quartz-like hardness, and inability to scratch it with a steel knife; glass or paint may scratch or chip. Common sources include Brazil, Uruguay, India, Madagascar, and Mexico.