igneous
Quartz–feldspar pegmatite mineral specimen
Quartz (SiO₂) with potassium feldspar, albite, mica, and likely garnet or tourmaline
AI-generated identification · may be incorrectCoarse interlocking crystals with translucent to milky quartz, white feldspar, pink to reddish crystals, and dark mica or tourmaline; quartz hardness 7, feldspar 6–6.5, mica 2–3, vitreous to pearly luster, irregular cleavage in quartz and strong cleavage in feldspar/mica.
Identified More igneous →
Explore Quartz–feldspar pegmatite mineral specimen in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Coarse interlocking crystals with translucent to milky quartz, white feldspar, pink to reddish crystals, and dark mica or tourmaline; quartz hardness 7, feldspar 6–6.5, mica 2–3, vitreous to pearly luster, irregular cleavage in quartz and strong cleavage in feldspar/mica.
Formation & geological history
A granitic pegmatite formed when volatile-rich residual magma cooled slowly in fractures, allowing exceptionally large crystals; commonly Precambrian to Mesozoic in age depending on locality.
Uses & applications
Collected as a mineral specimen and sometimes used as lapidary material; pegmatites are important sources of feldspar, mica, lithium minerals, beryl, and tourmaline.
Geological facts
The pink-red crystals may be potassium feldspar, iron-stained quartz, garnet, or another accessory mineral; exact identification requires crystal shape, hardness, and testing.
Field identification & locations
Look for very coarse crystals, glassy quartz, blocky feldspar, and flaky mica—diagnostic of pegmatite. Common worldwide in granitic terrains, including Brazil, Madagascar, the United States, and Pakistan.
