Milky Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
Rock Type: mineral

Physical Properties
Hardness: 7 on Mohs scale; Color: Milky white to opaque; Luster: Vitreous (glassy) to waxy; Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65
Formation & Geological History
Formed through hydrothermal activity or crystallization from cooling magma (igneous veins). This specific specimen appears to be water-worn, smoothed by river or coastal erosion over thousands of years.
Uses & Applications
Used in glassmaking, electronics (piezoelectric properties), abrasives, and as decorative landscaping stone. Polished versions are often used in low-cost jewelry or as 'worry stones'.
Geological Facts
Milky quartz gets its white color from tiny bubbles of gas or liquid trapped during the crystal's growth. It is the most common variety of crystalline quartz on Earth.
Field Identification & Locations
Identify in the field by its hardness (it will scratch glass and steel), white color, and lack of cleavage. Common in riverbeds, beaches, and mountain trails worldwide.
Identified on: 4/26/2026
Mode: Standard