mineral

Smoky quartz cluster

Quartz, silicon dioxide (SiO₂), likely smoky variety with minor iron-related color centers

AI-generated identification · may be incorrect

Transparent to translucent gray-brown crystals with vitreous luster and typical hexagonal prismatic form; Mohs hardness 7, no cleavage, conchoidal fracture, specific gravity about 2.65. The specimen appears partly coated or intergrown with darker matrix minerals.

Identified September 20, 2026More mineral →

Explore Smoky quartz cluster in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Quartz crystallizes from silica-rich hydrothermal fluids in fractures, cavities, and pegmatites, commonly during late stages of granitic activity. In the Bohemian/Vogtland region near 50.3°N, 12.3°E, quartz-bearing granites, pegmatites, and hydrothermal veins make this identification geologically plausible; age is commonly Variscan, roughly 330–300 million years.

Uses & applications

Used for mineral collecting, carvings, and occasionally gemstones; industrial quartz is important in glass, electronics, abrasives, and foundry materials. This small natural cluster has mainly decorative and specimen value.

Geological facts

Smoky coloration results from radiation-induced color centers associated with trace aluminum, often enhanced naturally in granite environments. Heating can remove the smoky color, producing colorless or yellow quartz.

Field identification & locations

Identify by hardness, glassy luster, hexagonal crystal faces, lack of cleavage, and inability to scratch it with a steel knife; avoid confusing it with glass or calcite. Common sources include granitic terrains of Germany, Czechia, Switzerland, Brazil, and the United States.