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

Physical Properties
Hardness: 7 on Mohs scale; Color: Cloudy white to yellowish-tan due to impurities; Luster: Vitreous to greasy; 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 specific specimen appears to be a water-worn or weathered pebble likely sourced from a stream or alluvial deposit.
Uses & Applications
Used in the production of glass, ceramics, and abrasives. Historically used for making tools; currently popular as a garden stone or for metaphysical collecting.
Geological Facts
Quartz is the second most abundant mineral in Earth's continental crust. The 'cloudy' or 'milky' appearance is caused by tiny inclusions of gas or liquid trapped during crystal growth.
Field Identification & Locations
Identify in the field by its ability to scratch glass, its lack of cleavage, and its waxy/greasy luster on broken surfaces. It is ubiquitous in riverbeds and mountainous regions worldwide.
Identified on: 4/18/2026
Mode: Standard