mineral

Milky quartz in a quartz-rich rock

Quartz, silicon dioxide (SiO₂); likely massive quartz or quartzite fragment

AI-generated identification · may be incorrect

White to translucent, vitreous to sugary luster, irregular fracture, no obvious cleavage; Mohs hardness 7 and specific gravity about 2.65. The rough triangular piece appears quartz-rich, with possible minor feldspar or mica inclusions.

Identified August 27, 2026More mineral →

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Physical properties

Formation & geological history

Quartz crystallizes from silica-rich hydrothermal fluids or forms during igneous and metamorphic processes; quartzite forms when sandstone recrystallizes under heat and pressure. The specimen’s exact age and origin cannot be determined from the image.

Uses & applications

Used in glass, ceramics, engineered stone, abrasives, electronics, and countertops; attractive pieces are collected as mineral specimens. This example appears to have modest decorative value.

Geological facts

Quartz is one of Earth’s most abundant minerals and is the defining component of many veins and quartzites. Milky color results mainly from microscopic fluid inclusions and fractures.

Field identification & locations

Identify it by its hardness—quartz scratches glass—and lack of cleavage; it should not fizz in dilute acid. Common locations include hydrothermal veins, pegmatites, sandstone terrains, and metamorphic belts.