mineral

Quartz (Fieldstone/Pebble)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale. Color: Tan, beige, translucent white with iron staining. Luster: Vitreous to waxy. Crystal Structure: Hexagonal (though not visibly crystallized here). Cleavage: None (conchoidal fracture). Specific gravity: 2.65.

Hardness: 7 on Mohs scale
Color: Tan, beige, translucent white with iron staining
Luster: Vitreous to waxy

Identified March 14, 2026More mineral →

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Physical properties

Formation & geological history

Formed through the cooling of silica-rich magma or precipitation from hydrothermal veins. This specific specimen shows signs of mechanical weathering and erosion, likely found in a stream bed or glacial deposit. Its geological age can range from millions to billions of years depending on the parent rock.

Uses & applications

Used in glassmaking, abrasives, and electronics (piezoelectric). In this tumbled form, it is primarily used for landscaping, construction aggregate, or as a common collector's 'pocket stone'.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. It is highly resistant to chemical and physical weathering, which is why it often remains as rounded pebbles long after other minerals have broken down into clay.

Field identification & locations

Identify in the field by its inability to be scratched by a steel knife (hardness 7) and its lack of cleavage. It is found globally in almost every geological environment, particularly in riverbeds, beaches, and soil.