Quartz (Smoky/Milky variant)

Silicon Dioxide (SiO2)

Rock Type: mineral

Quartz (Smoky/Milky variant)

Physical Properties

Hardness: 7 on Mohs scale. Color: Translucent tan to smoky brown. Luster: Vitreous when clean, currently dull due to surface weathering. Crystal structure: Trigonal/Hexagonal. Cleavage: None (conchoidal fracture). Specific gravity: 2.65.

Formation & Geological History

Formed through the cooling of silica-rich magma or from hydrothermal veins. This specimen appears water-worn or weathered, likely found in a secondary alluvial deposit or soil.

Uses & Applications

Quartz is used extensively in glassmaking, electronics (piezoelectric properties), and as an abrasive in construction. Lower grade specimens like this are primarily of interest to beginner collectors.

Geological Facts

Quartz is the second most abundant mineral in Earth's continental crust. Its name comes from the German word 'Quarz', which has Slavic origins meaning 'hard'.

Field Identification & Locations

Identify in the field by its hardness (it should scratch glass) and lack of cleavage. Commonly found in most geological environments globally, especially in gravel pits, riverbeds, and mountain ranges.

Identified on: 5/9/2026

Mode: Standard