Quartz Vein in Siltstone

Physical Properties

Hardness: Quartz (7), Siltstone (3-5); Color: White vein on dark brown/reddish matrix; Luster: Glassy (quartz) to dull (siltstone); Structure: Hexagonal crystals (microscopic) in vein.

Formation & Geological History

Formed through the deposition of fine-grained sediment (siltstone) followed by hydrothermal activity where silica-rich fluids filled fractures to create the white quartz vein.

Uses & Applications

Primarily of interest to mineral collectors or as a geological teaching specimen; larger deposits of quartz are used in glass-making and electronics.

Geological Facts

Quartz veins are often 'paths' for gold and other precious metals, though this small specimen is likely just common milky quartz.

Field Identification & Locations

To identify in the field, look for the sharp contrast between the white, hard crystalline material (quartz) and the softer, earthy, reddish-brown host rock.

Identified on: 4/19/2026

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