mineral

Milky quartz in weathered host rock

Quartz, silicon dioxide (SiO₂), likely with iron-stained feldspar or altered matrix

AI-generated identification · may be incorrect

White to translucent, vitreous-to-waxy luster, massive rather than well-crystallized; Mohs hardness 7, no cleavage, uneven to conchoidal fracture, specific gravity about 2.65. The brown coating and attached fragments likely represent iron oxides and weathered silicate rock.

Identified September 4, 2026More mineral →

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Physical properties

Formation & geological history

Quartz commonly crystallizes from silica-rich hydrothermal fluids, pegmatites, or cavities in igneous and metamorphic rocks; the specimen’s exact age and host rock cannot be determined from the image. Surface iron staining formed later during weathering.

Uses & applications

Used for glass, ceramics, abrasives, engineered stone, and silica products; attractive pieces are collected, though this specimen appears mostly ordinary material.

Geological facts

Quartz is one of Earth’s most abundant minerals and is piezoelectric. Milky appearance results from microscopic fluid inclusions, fractures, or dispersed defects.

Field identification & locations

Identify it by its white translucent body, glassy sheen, lack of cleavage, and ability to scratch ordinary glass; a steel nail should not scratch it. Common worldwide, especially in quartz veins and granitic terrains.