mineral

Tumbled chalcedony and agate

Microcrystalline quartz (SiO₂), chiefly chalcedony with possible quartz/agate banding

AI-generated identification · may be incorrect

Pale gray, white, lavender, and tan translucent pieces with waxy to vitreous luster and conchoidal fracture; hardness about 6.5–7 Mohs, no obvious cleavage, cryptocrystalline quartz structure, specific gravity ~2.6. The rounded surfaces indicate tumbling or natural water wear.

Identified September 1, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich groundwater fills cavities and fractures in volcanic rock, precipitating chalcedony and occasionally layered agate; some lavender coloration may reflect trace iron or manganese. Exact age cannot be determined visually; material in the Fraser Valley region commonly derives from glacially transported volcanic and metamorphic debris.

Uses & applications

Used for inexpensive cabochons, beads, carvings, décor, and lapidary practice. Common tumbled pieces generally have modest commercial value.

Geological facts

The circular markings and cloudy translucent zones are consistent with agate or chalcedony growth textures, though the photograph does not support a precise variety identification.

Field identification & locations

Likely regional glacial or stream gravel, but confirmation requires a fresh surface, strong backlighting, and hardness testing: it should scratch ordinary glass, while steel should not scratch it readily. Common worldwide and plausible near 49.0°N, 122.3°W.