mineral

Weathered quartz-rich rock or fossil fragment

Indeterminate; likely quartz-bearing sandstone or siliceous fossil material

AI-generated identification · may be incorrect

Small tan-gray, irregular specimen with a dull to slightly waxy luster, granular texture, and weathered surfaces. Likely hardness about 6–7 Mohs if quartz-rich; cleavage is absent and specific gravity is approximately 2.5–2.7.

Identified September 13, 2026More mineral →

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Physical properties

Formation & geological history

Could represent silicified sandstone, chert, or a mineralized fossil fragment formed by silica cementation or replacement in sedimentary environments. Its geological age cannot be determined from the photograph.

Uses & applications

Primarily a curiosity or teaching specimen; quartz-rich material may be used as aggregate, but this piece has no apparent industrial or gem value.

Geological facts

The shape and pitted surface could be fossil-related, but no diagnostic structure is visible; the dark line may be a fracture, coating, or sedimentary boundary.

Field identification & locations

Common possibilities include sandstone, chert, and silicified fossil material. Test with a steel file or glass: quartz-rich material should scratch glass and resist steel; a close-up of fresh broken surface and acid testing would improve identification.