igneous
Quartz-rich pegmatite
Granitic pegmatite, composed mainly of quartz and feldspar with dark mica or other accessory minerals
AI-generated identification · may be incorrectCoarse, irregularly intergrown white to tan crystals with scattered dark minerals; quartz hardness 7 and feldspar about 6 Mohs, typically vitreous to dull. The image suggests a coarse crystalline texture, but mineral identification and composition cannot be confirmed from appearance alone.
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Physical properties
Coarse, irregularly intergrown white to tan crystals with scattered dark minerals; quartz hardness 7 and feldspar about 6 Mohs, typically vitreous to dull. The image suggests a coarse crystalline texture, but mineral identification and composition cannot be confirmed from appearance alone.
Formation & geological history
Pegmatite crystallizes from late-stage, silica-rich magma, often in veins cutting older igneous or metamorphic rocks. Its age depends on the local geology and cannot be determined from the image.
Uses & applications
Quartz and feldspar pegmatites are sources of industrial minerals; attractive crystals may be collected or used decoratively. This specimen appears too weathered and massive for gem use.
Geological facts
Pegmatites can contain exceptionally large crystals and sometimes rare minerals such as tourmaline, beryl, or lithium-bearing minerals.
Field identification & locations
Look for very coarse interlocking crystals, commonly quartz, feldspar, and mica; field identification is best confirmed by testing individual minerals. Found worldwide in association with granites; location is unknown here.
