mineral

Tumbled clear quartz (rock crystal)

Quartz, silicon dioxide (SiO₂)

AI-generated identification · may be incorrect

Hardness 7 Mohs; colorless and transparent with vitreous luster, conchoidal fracture, no cleavage, and trigonal crystal structure. The smoothly rounded shape indicates mechanical tumbling and polishing.

Identified September 8, 2026More mineral →

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Physical properties

Formation & geological history

Quartz crystallizes from silica-rich fluids in igneous, hydrothermal, and metamorphic environments, commonly in geodes and veins. Individual crystals may span a wide geological age range; the specimen’s age cannot be determined visually.

Uses & applications

Used for ornamental stone, lapidary carvings, meditation objects, optics, glass, ceramics, and electronics. This small tumbled piece has modest decorative value.

Geological facts

Clear quartz is often called rock crystal; internal reflections or faint cloudy zones are natural. Similar-looking man-made glass is softer and may show bubbles or flow textures.

Field identification & locations

Identify by its excellent scratch resistance, cool glassy feel, and lack of cleavage; quartz can scratch ordinary glass. Common sources include Brazil, Madagascar, the United States, and China.