mineral

Polished agate or chalcedony pebble

Microcrystalline quartz, SiO₂ (chalcedony; exact identification uncertain from the image)

AI-generated identification · may be incorrect

Pale cream to gray, translucent in places, with a smooth polished surface and waxy-to-vitreous luster. Quartz hardness is about 7 Mohs; crystal structure is microcrystalline and cleavage is absent.

Identified October 4, 2026More mineral →

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At a glance

Common name: Polished agate or chalcedony pebble
Scientific name: Microcrystalline quartz, SiO₂ (chalcedony; exact identification uncertain from the image)
Category: mineral
Identified: October 4, 2026
Method: Standard

AI Estimated Value

Approximately $2–$20 for a small, common polished pebble; higher value requires distinctive pattern, quality, or confirmed identification.

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

Pale cream to gray, translucent in places, with a smooth polished surface and waxy-to-vitreous luster. Quartz hardness is about 7 Mohs; crystal structure is microcrystalline and cleavage is absent.

Formation & geological history

Silica-rich fluids deposited quartz in cavities or fractures, later forming chalcedony; the pebble appears naturally rounded and human-polished. Such deposits occur across many geological ages.

Uses & applications

Used for decorative objects, lapidary work, and inexpensive jewelry.

Geological facts

Agate is a banded variety of chalcedony, but no clear banding is visible here; the specimen could instead be another quartz-rich stone.

Field identification & locations

Look for hardness near 7, conchoidal fracture, and translucent edges; common sources include volcanic rocks and alluvial gravels worldwide. The image alone does not establish the precise variety.