gemstone

Cut quartz crystal (likely rock crystal)

Quartz, silicon dioxide (SiO₂), trigonal crystal system

AI-generated identification · may be incorrect

Colorless to pale blue and strongly transparent, with vitreous luster and conchoidal fractures; Mohs hardness 7 and specific gravity about 2.65. The faceted, oval form is human-cut and displays rainbow-like spectral reflections and internal fractures.

Identified September 17, 2026More gemstone →

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Physical properties

Formation & geological history

Quartz crystallizes from silica-rich hydrothermal fluids, pegmatites, and igneous cavities, commonly during Precambrian to recent geological events. The pictured specimen is a polished/cut geological material rather than a natural crystal face.

Uses & applications

Used as a gemstone, ornament, display piece, and in optical or piezoelectric applications when exceptionally clear; quartz is also important in glass, electronics, and construction aggregate.

Geological facts

The apparent blue and rainbow flashes are mainly caused by dispersion, facet reflections, and fracture planes, not necessarily by blue coloration. Natural inclusions and veils can help distinguish quartz from manufactured glass.

Field identification & locations

Identify by its hardness, cool glassy feel, conchoidal fracture, and lack of glass bubbles; it scratches ordinary glass but not corundum. Common sources include Brazil, Madagascar, the United States, and the Alps.