mineral

Quartz Pebble (Citrine-colored or Stained Quartz)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Translucent yellowish-brown to tan; Luster: Vitreous (glassy) to waxy when weathered; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Translucent yellowish-brown to tan
Luster: Vitreous (glassy) to waxy when weathered

Identified March 21, 2026More mineral →

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Physical properties

Formation & geological history

Formed through hydrothermal processes in igneous or metamorphic veins. This specific specimen is a 'water-worn' pebble, meaning it was eroded from its host rock and tumbled in a river, stream, or beach environment, giving it a smooth, rounded shape.

Uses & applications

Used in landscaping, construction aggregate, and as a source for silicon in industrial manufacturing. High-quality transparent versions (Citrine) are used in jewelry. As a common pebble, it is mostly for hobbyist collecting.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Its yellow color often comes from iron impurities or 'iron staining' from the surrounding soil, especially in river-rolled specimens like this one.

Field identification & locations

Identify in the field by its hardness (it will easily scratch glass) and lack of cleavage (it breaks with curved, shell-like surfaces). Commonly found in riverbeds, glacial tills, and beaches worldwide. Collectors looks for clarity or unique internal inclusions.

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