mineral

Iron-stained quartz or chert fragment

Quartz (SiO₂), possibly microcrystalline quartz/chert with limonite staining

AI-generated identification · may be incorrect

Small tan-orange, opaque to weakly translucent fragment with earthy/waxy luster and irregular fractures; quartz has Mohs hardness 7, no cleavage, and specific gravity about 2.65. The surface appears weathered or naturally coated with iron oxides, though the photo cannot confirm composition.

Identified September 7, 2026More mineral →

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Physical properties

Formation & geological history

Likely formed as silica-rich vein material or microcrystalline sedimentary chert, later fractured and stained by oxidized iron-bearing groundwater; geological age is indeterminate from the image.

Uses & applications

Common quartz/chert is used as aggregate, abrasives, and historically for stone tools; attractive pieces may be kept as curios or lapidary rough, but this specimen has little commercial value.

Geological facts

Orange-brown coloration commonly comes from limonite or hematite coatings rather than quartz itself. A steel file should not easily scratch quartz, while quartz can scratch ordinary glass.

Field identification & locations

Common in weathered veins, gravel, soils, and sedimentary terrains worldwide; inspect for glass-scratching ability, a white streak, and lack of cleavage. It could alternatively be a low-grade iron-rich concretion or ceramic-like fragment, so testing is needed.