Rock Identifier
Likely weathered feldspar-rich stone (Feldspar, probably microcline or orthoclase (KAlSi₃O₈), possibly altered pegmatite material) — mineral
mineral

Likely weathered feldspar-rich stone

Feldspar, probably microcline or orthoclase (KAlSi₃O₈), possibly altered pegmatite material

AI-generated identification · may be incorrect

Cream to tan, opaque, with blocky fragments and likely cleavage planes; vitreous to dull luster. Feldspar hardness is about 6 Mohs, with two cleavages near 90° and specific gravity around 2.55–2.63. Dark markings may be iron/manganese staining or attached matrix.

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Physical properties

Cream to tan, opaque, with blocky fragments and likely cleavage planes; vitreous to dull luster. Feldspar hardness is about 6 Mohs, with two cleavages near 90° and specific gravity around 2.55–2.63. Dark markings may be iron/manganese staining or attached matrix.

Formation & geological history

Forms in igneous rocks such as granite and pegmatite, where feldspar crystals crystallize from cooling magma; alteration and weathering produce the tan surface. A precise age cannot be determined from the photograph.

Uses & applications

Used in ceramics, glass, abrasives, and occasionally as decorative or lapidary material; these weathered fragments have little jewelry value.

Geological facts

The blocky shape and apparent right-angle cleavage strongly favor feldspar over quartz, which lacks cleavage and commonly fractures conchoidally.

Field identification & locations

The specimen is consistent with feldspar-bearing granite or pegmatite, plausible around Senegal’s Precambrian basement and pegmatitic terrains, though the image alone cannot establish locality. Check for two cleavages near 90°, hardness sufficient to scratch glass, and absence of quartz-like conchoidal fracture.