mineral

Tumbled chalcedony or quartz pebble

Microcrystalline quartz, SiO₂ (likely chalcedony; exact identification requires testing)

AI-generated identification · may be incorrect

Small rounded cream-white pebble with a waxy to dull luster and possible slight translucency; quartz hardness is Mohs 7, with no cleavage and conchoidal fracture. Its smooth shape indicates natural or human tumbling.

Identified September 4, 2026More mineral →

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At a glance

Common name: Tumbled chalcedony or quartz pebble
Scientific name: Microcrystalline quartz, SiO₂ (likely chalcedony; exact identification requires testing)
Category: mineral
Identified: September 4, 2026
Method: Standard

AI Estimated Value

About $1–$10 as a small common tumbled specimen; potentially $10–$30 if it proves to be unusually attractive agate or high-quality chalcedony.

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

Formed when silica-rich groundwater filled cavities or fractures, commonly as chalcedony in volcanic rocks, or derived from weathered quartz veins and transported as alluvium. Chalcedony forms across many geological ages; the specimen’s age cannot be determined visually.

Uses & applications

Used for beads, carvings, lapidary pieces, and decorative stone; similar material is also used in abrasives and industrial silica. This small common pebble has little commercial value.

Geological facts

Cream chalcedony may be called white agate when it shows banding, though no diagnostic banding is visible here. A steel file should not scratch quartz, while glass can be scratched by it.

Field identification & locations

Common in gravel beds and volcanic terrains worldwide, including Brazil, Uruguay, India, Madagascar, and the western United States. Confirm with hardness, translucency, and specific gravity tests; visual identification alone is not definitive.