mineral

Likely weathered feldspar-rich rock fragment

Uncertain; possibly orthoclase or microcline feldspar in a pegmatitic rock

AI-generated identification · may be incorrect

Tan to honey-brown, translucent at thin edges, with a vitreous to dull luster and blocky cleavage surfaces. Feldspar hardness is about 6–6.5 Mohs, with two cleavages near 90°; the image is partly obscured, limiting certainty.

Identified August 22, 2026More mineral →

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Physical properties

Formation & geological history

Feldspar crystallizes from cooling silica-rich magma, commonly in granite and pegmatite; such rocks typically formed hundreds of millions to billions of years ago. Brown coloration may result from weathering or iron staining.

Uses & applications

Feldspar is used in glass, ceramics, abrasives, and occasionally as a decorative or collectible mineral. This rough fragment has little commercial value unless crystals or unusual color are present.

Geological facts

The apparent blocky shape and cleavage are consistent with feldspar, but quartz, calcite, or a weathered rock fragment remain possible without testing. A white streak, glass-scratch test, and cleavage inspection would improve identification.

Field identification & locations

Common in granite, pegmatite, gneiss, and feldspar-rich sands worldwide. Check for two cleavage planes, hardness sufficient to scratch glass, and lack of strong fizzing with dilute acid.