Quartz (Smoky/Milky variety)

Physical Properties

Hardness: 7 (Mohs scale); Color: Grayish-white to translucent; Luster: Vitreous (glassy); Crystal Structure: Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & Geological History

Formed through the cooling and crystallization of silica-rich magma or from hydrothermal veins. It can be found in a vast range of geological ages from Precambrian to recent, often in igneous or metamorphic environments.

Uses & Applications

Used in glass manufacturing, electronics (due to piezoelectric properties), abrasive production, and as a gemstone for jewelry or metaphysical collecting.

Geological Facts

Quartz is the second most abundant mineral in Earth's continental crust. It is highly resistant to both chemical and physical weathering, which is why it is often the primary component of beach sand.

Field Identification & Locations

Identify in the field by its hardness (it will scratch glass), glassy luster, and the lack of cleavage (it breaks in irregular, curved surfaces like glass). It is found globally, notably in Brazil and the USA.

Identified on: 4/20/2026

Mode: Standard