mineral

Tumbled quartz (milky quartz)

Quartz, silicon dioxide (SiO₂)

AI-generated identification · may be incorrect

White to cream, translucent, vitreous-to-waxy luster, and rounded from tumbling; hardness 7 Mohs, no cleavage, conchoidal fracture, hexagonal crystal structure, and specific gravity about 2.65.

Identified September 18, 2026More mineral →

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Physical properties

White to cream, translucent, vitreous-to-waxy luster, and rounded from tumbling; hardness 7 Mohs, no cleavage, conchoidal fracture, hexagonal crystal structure, and specific gravity about 2.65.

Formation & geological history

Forms when silica-rich fluids crystallize in igneous, hydrothermal, or metamorphic environments; quartz is common from Precambrian rocks through the present. The specimen has been human-polished and may show iron-oxide staining.

Uses & applications

Used as a low-cost lapidary stone, decorative pebble, and occasionally in jewelry; quartz is also important industrially for glass, ceramics, electronics, and abrasives.

Geological facts

Milky appearance results from microscopic fluid inclusions, fractures, or impurities that scatter light. It can produce a diagnostic scratch on ordinary glass.

Field identification & locations

Common worldwide, especially in granite pegmatites, quartz veins, and metamorphic rocks. Confirm with hardness and lack of cleavage; avoid confusing it with calcite, which is much softer and cleaves readily.