igneous
Quartz-rich pegmatite, possibly with mica
Granite/pegmatite composed mainly of quartz (SiO₂), feldspar, and likely biotite or muscovite mica
AI-generated identification · may be incorrectCoarse-grained, white to gray and brownish, with a vitreous-to-pearly luster; quartz hardness is 7, feldspar 6–6.5, and mica 2–3. Crystals appear interlocking, though the specimen is too weathered for confident mineral identification.
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Physical properties
Coarse-grained, white to gray and brownish, with a vitreous-to-pearly luster; quartz hardness is 7, feldspar 6–6.5, and mica 2–3. Crystals appear interlocking, though the specimen is too weathered for confident mineral identification.
Formation & geological history
Likely formed as a slowly cooled, silica-rich igneous intrusion or pegmatite vein, probably during Precambrian to younger continental plutonic activity. Exact age and locality require geological context or laboratory testing.
Uses & applications
Common pegmatite is mainly a teaching and collector specimen; related deposits may supply feldspar, quartz, mica, lithium, beryl, or tourmaline. It has little value as construction stone at this small size.
Geological facts
The apparent sparkling or flaky areas may be mica, while translucent whitish grains are likely quartz or feldspar. A streak, hardness, and acid test would help distinguish the minerals.
Field identification & locations
Look for coarse interlocking grains, glassy quartz, blocky feldspar, and shiny flaky mica; common in granite terrains and pegmatite districts worldwide. Estimated value: $2–$15 for an ordinary hand specimen, more if rare accessory crystals are confirmed.
