Quartz (Citrine or Smoky variant)

Physical Properties

Hardness: 7 on Mohs scale; Color: Pale yellowish-grey; Luster: Vitreous (glassy); Crystal structure: Hexagonal/Trigonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65.

Formation & Geological History

Formed in igneous pegmatites or hydrothermal veins. This specimen appears water-worn, suggesting it was found in an alluvial (river or stream) deposit.

Uses & Applications

Used in electronics (piezoelectric properties), glassmaking, watchmaking, jewelry as semi-precious gemstones, and by mineral collectors.

Geological Facts

Quartz is the second most abundant mineral in Earth's continental crust. Citrine, the yellow variety, is extremely rare in nature; most commercial citrine is heat-treated amethyst or smoky quartz.

Field Identification & Locations

Identify by its ability to scratch glass and lack of cleavage. Look for the characteristic glassy, shell-like fracture pattern. Often found in gravel beds or near granite outcrops.

Identified on: 4/15/2026

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