Smoky Quartz with Iron Inclusions

Physical Properties

Hardness: 7 on Mohs scale; Color: Grayish-brown to black with reddish iron staining; Luster: Vitreous (glassy); Crystal Structure: Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & Geological History

Formed in pegmatites and hydrothermal veins through the crystallization of silica-rich fluids. The smoky color is caused by natural irradiation of aluminum impurities within the crystal lattice.

Uses & Applications

Used primarily in lapidary work, jewelry, and crystal healing collections. High-quality clear pieces are used for optical instruments and electronics.

Geological Facts

Smoky quartz is the national gem of Scotland, where it is known as Cairngorm. The dark color can be faded by exposure to high temperatures or UV Light.

Field Identification & Locations

Identify in the field by its hardness (scratches glass), lack of cleavage, and translucent to transparent appearance. Commonly found alongside feldspar and mica in granite-rich regions.

Identified on: 4/30/2026

Mode: Standard