Gray Quartz (Tumbled)

Physical Properties

Hardness: 7 on Mohs scale; Color: Gray to translucent cloudy; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: Indistinct/Conchoidal fracture; Specific Gravity: 2.65

Formation & Geological History

Quartz forms in a wide variety of environments, primarily through the cooling of silica-rich magma or from hydrothermal veins. This specific specimen appears to be a river-worn or mechanically tumbled pebble, likely extracted from sedimentary deposits where it accumulated due to its high resistance to weathering.

Uses & Applications

Used in glass making, abrasive manufacturing, electronics (due to piezoelectric properties), and ornamental purposes like jewelry or decorative stone for landscaping and aquariums.

Geological Facts

Quartz is the second most abundant mineral in Earth's continental crust. Its name comes from the German word 'quarz', which has roots in Slavic meaning 'hard'. It is highly resistant to both chemical and physical weathering.

Field Identification & Locations

Identified in the field by its hardness (scratches glass), lack of cleavage, and conchoidal (shell-like) fracture patterns. It is found globally in almost every geological environment. Collectors should look for translucency and the absence of bubbles (which would indicate glass).

Identified on: 5/13/2026

Mode: Standard