mineral
Likely milky quartz
Quartz (silicon dioxide, SiO₂), possibly quartz-rich rock or calcite
AI-generated identification · may be incorrectWhite, opaque to translucent, glassy-to-dull luster with irregular fracture; quartz hardness is 7, no cleavage, and specific gravity about 2.65. The granular, crumbly appearance could also indicate calcite, which is softer (Mohs 3) and effervesces in dilute acid.
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Physical properties
White, opaque to translucent, glassy-to-dull luster with irregular fracture; quartz hardness is 7, no cleavage, and specific gravity about 2.65. The granular, crumbly appearance could also indicate calcite, which is softer (Mohs 3) and effervesces in dilute acid.
Formation & geological history
Quartz commonly crystallizes from silica-rich hydrothermal fluids or forms in igneous and metamorphic rocks; specimens may be Precambrian to recent. Exact identification and age cannot be determined from the photograph alone.
Uses & applications
Common quartz is used in glass, ceramics, abrasives, engineered stone, and electronics; attractive pieces may be collected but this specimen appears low grade.
Geological facts
Quartz is one of Earth’s most abundant minerals and has a distinctive six-sided crystal system when well formed.
Field identification & locations
Look for glassy surfaces and inability to scratch with a steel knife for quartz; a vinegar or dilute hydrochloric-acid fizz suggests calcite instead. Common worldwide, especially in veins and granitic or metamorphic terrains.
