Rock Identifier
Likely smoky quartz pendant (Smoky quartz, silicon dioxide (SiO₂), quartz variety colored by irradiation-related defects) — gemstone
gemstone

Likely smoky quartz pendant

Smoky quartz, silicon dioxide (SiO₂), quartz variety colored by irradiation-related defects

AI-generated identification · may be incorrect

The round, transparent-to-translucent brown stone has vitreous luster and appears faceted or polished in a metal setting. Mohs hardness 7; trigonal crystal structure; no cleavage, conchoidal fracture; specific gravity about 2.65.…

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Physical properties

The round, transparent-to-translucent brown stone has vitreous luster and appears faceted or polished in a metal setting. Mohs hardness 7; trigonal crystal structure; no cleavage, conchoidal fracture; specific gravity about 2.65. Exact identification is uncertain from the jewelry photograph, and brown topaz, zircon, or glass are alternatives.

Formation & geological history

Smoky quartz forms in silica-rich hydrothermal veins, pegmatites, and cavities in igneous rocks; its brown color commonly develops through natural irradiation of aluminum-bearing quartz. It ranges from ancient to geologically recent, depending on the host rock.

Uses & applications

Used as an inexpensive gemstone in pendants and other jewelry, and collected as crystals. The surrounding chain and setting are human-made but the pendant stone is geological material.

Geological facts

Color may fade with prolonged strong light or heating; very dark material can be artificially irradiated. Quartz is one of Earth’s most abundant minerals.

Field identification & locations

Check for quartz’s hardness, glassy luster, conchoidal fracture, and lack of cleavage; a gemological refractometer or spectroscopy is needed for confirmation. Common sources include Brazil, Madagascar, Switzerland, and the United States.