igneous
Quartz-rich granitic pegmatite
Quartz–feldspar pegmatite, with probable mica and iron-oxide staining
AI-generated identification · may be incorrectHardness about 6–7 (quartz); white to gray translucent quartz with pinkish-brown weathering, vitreous luster, and coarse interlocking crystals. Quartz lacks cleavage; feldspar shows two cleavage planes. Specific gravity roughly 2.6–2.7.
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Physical properties
Hardness about 6–7 (quartz); white to gray translucent quartz with pinkish-brown weathering, vitreous luster, and coarse interlocking crystals. Quartz lacks cleavage; feldspar shows two cleavage planes. Specific gravity roughly 2.6–2.7.
Formation & geological history
A coarse-grained igneous rock formed when silica-rich magma crystallized slowly, commonly in a late-stage granitic intrusion or pegmatite vein. Such rocks are generally Precambrian to Phanerozoic, depending on locality.
Uses & applications
Commonly used as a source of quartz and feldspar, aggregate, and occasionally decorative stone; attractive crystals may be collected, though this specimen appears ordinary rather than gem grade.
Geological facts
The bluish translucent areas are likely quartz, while pink or cream grains may be feldspar; brown coloration is probably limonite or other iron oxides from weathering.
Field identification & locations
Identify it by its very coarse texture, glassy quartz, blocky feldspar, and lack of layering or foliation. Common in granitic terrains and pegmatite districts worldwide; a fresh fracture and streak test help confirm quartz.
