Milky Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Rock Type: mineral

Milky Quartz Pebble

Physical Properties

Hardness: 7 (Mohs scale); Color: Opaque white to cream; Luster: Vitreous to waxy; Crystal structure: Hexagonal/Trigonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65.

Formation & Geological History

Quartz forms in a wide variety of environments, including igneous intrusions (hydrothermal veins), metamorphic rocks, and sedimentary deposits. This specific specimen is a water-worn pebble, likely rounded through mechanical erosion in a river or beach environment.

Uses & Applications

Milky quartz is used in glassmaking, construction as abrasive or aggregate, and in electronics as a source of silicon. Tumbled stones are used for decorative purposes and jewelry.

Geological Facts

Milky quartz gets its white color from tiny microscopic fluid inclusions of gas or liquid trapped during the crystal's growth. It is one of the most common minerals on Earth's crust.

Field Identification & Locations

Identify in the field by its hardness (will scratch glass), lack of cleavage, and translucent to opaque white appearance. It is commonly found in gravel pits, mountain streams, and along coastlines.

Identified on: 4/25/2026

Mode: Standard