Quartz Pebble
Silicon dioxide (SiO2)
Rock Type: mineral

Physical Properties
Hardness: 7 (Mohs scale); Color: White to translucent; Luster: Vitreous to waxy (when river-worn); Crystal structure: Hexagonal/Trigonal; Cleavage: None/Conchoidal fracture; Specific gravity: 2.65
Formation & Geological History
Formed from cooling magma or precipitation in hydrothermal veins. This specific specimen has been rounded and smoothed by mechanical weathering in high-energy water environments like rivers or beaches.
Uses & Applications
Common quartz is used for abrasive blasting, glass making, and as a component in concrete. Smooth pebbles are used for garden landscaping, aquarium decor, and home decorations.
Geological Facts
Quartz is the second most abundant mineral in Earth's continental crust. It is extremely chemically stable and resistant to weathering, which is why it often remains as pebbles while other minerals break down.
Field Identification & Locations
Identify in the field by its hardness (it can scratch glass and steel knives) and lack of cleavage. Found globally in almost all riverbeds and coastal areas.
Identified on: 4/28/2026
Mode: Standard