mineral
Milky quartz (rough quartz fragment)
Quartz, silicon dioxide (SiO₂)
AI-generated identification · may be incorrectTypically Mohs hardness 7, vitreous to waxy luster, white to translucent coloration, and no cleavage; it shows irregular or conchoidal fracture and a trigonal crystal structure. The yellow-brown surface likely reflects iron-oxide staining or weathering.
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Physical properties
Typically Mohs hardness 7, vitreous to waxy luster, white to translucent coloration, and no cleavage; it shows irregular or conchoidal fracture and a trigonal crystal structure. The yellow-brown surface likely reflects iron-oxide staining or weathering.
Formation & geological history
Forms when silica-rich fluids crystallize in veins, cavities, or igneous and metamorphic rocks; individual specimens may range from Precambrian to recent geological settings. This fragment is too weathered and irregular to determine a precise locality or age.
Uses & applications
Used in glass, ceramics, abrasives, foundry materials, electronics, and engineered stone; attractive translucent pieces are used decoratively or as inexpensive specimens. It is generally low-value unless exceptionally clear, well-formed, or unusually colored.
Geological facts
Quartz is one of Earth’s most abundant minerals and is a major component of granite, sandstone, and many hydrothermal veins. The specimen’s translucent white body and hardness are consistent with quartz, though a simple glass-scratch test is not definitive.
Field identification & locations
Common worldwide, especially in hydrothermal veins and quartz-rich igneous or metamorphic terrains; test whether it scratches ordinary glass and inspect for conchoidal fracture. Avoid confusing it with calcite, which is softer and reacts readily with dilute acid.
