mineral

Likely milky quartz

Quartz (silicon dioxide, SiO₂), possibly quartz-rich rock or calcite

AI-generated identification · may be incorrect

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.

Identified September 8, 2026More mineral →

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Physical properties

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.