igneous
Quartz-rich pegmatite with black tourmaline
Granitic pegmatite composed chiefly of quartz, with black tourmaline (schorl); possibly feldspar
AI-generated identification · may be incorrectCoarse, irregular white-to-translucent quartz with black, elongated tourmaline masses. Quartz has Mohs hardness 7 and vitreous luster; schorl is about 7–7.5, typically opaque and prismatic. The specimen’s rounded shape may result from weathering or handling.
Identified More igneous →
Explore Quartz-rich pegmatite with black tourmaline in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Coarse, irregular white-to-translucent quartz with black, elongated tourmaline masses. Quartz has Mohs hardness 7 and vitreous luster; schorl is about 7–7.5, typically opaque and prismatic. The specimen’s rounded shape may result from weathering or handling.
Formation & geological history
Likely crystallized from volatile-rich granitic magma late in an intrusion, allowing coarse crystals to grow. Pegmatites commonly formed during the Precambrian through Cenozoic; this individual cannot be dated from the image.
Uses & applications
Quartz and tourmaline are used as mineral specimens and occasionally in jewelry; pegmatite minerals can also be sources of industrial minerals and gemstones.
Geological facts
Black tourmaline is the iron-rich tourmaline species schorl; quartz and tourmaline commonly occur together in granitic pegmatites.
Field identification & locations
Look for hard, glassy white quartz intergrown with opaque black tourmaline, often in elongated crystals; common in pegmatite districts worldwide. The visible material appears consistent with this association, though exact identification requires examination.
