mineral

Iron-stained quartz/pegmatite fragment

Quartz (SiO₂) with iron-oxide/hydroxide staining, possibly feldspar matrix

AI-generated identification · may be incorrect

Off-white to translucent quartz is coated by brown-orange limonite/goethite and dark iron oxides; glassy to earthy luster, massive texture, no obvious cleavage, Mohs hardness about 7 for quartz, specific gravity about 2.65.

Identified August 21, 2026More mineral →

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Physical properties

Formation & geological history

Likely formed in a hydrothermal vein or granitic pegmatite, where silica-rich fluids crystallized quartz and later weathering oxidized iron-bearing minerals. Exact age cannot be determined from the photograph; it may range from Paleozoic to younger depending on locality.

Uses & applications

Common material for mineral collecting and lapidary work; attractive portions may be polished, though heavy staining and fractures reduce gem value.

Geological facts

The brown coating is probably limonite/goethite rather than a distinct brown quartz variety. A steel blade should not easily scratch fresh quartz, while quartz can scratch ordinary glass.

Field identification & locations

Look for hard, glassy white/translucent areas, conchoidal fracture, and rusty coatings concentrated along cracks. Common in quartz veins, pegmatites, mine dumps, and weathered granitic terrain worldwide.