sedimentary

Quartz-veined Siltstone/Greywacke

Clastic Sedimentary Rock with Quartz Infill (SiO2 vein)

AI-generated identification · may be incorrect

Hardness: 6-7 (Mohs). Color: Grey-green matrix with a white/translucent vein. Luster: Dull/earthy matrix, vitreous vein. Non-foliated, fine-grained texture.

Hardness: 6-7 (Mohs)
Color: Grey-green matrix with a white/translucent vein
Luster: Dull/earthy matrix, vitreous vein

Identified May 18, 2026More sedimentary →

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Physical properties

Hardness: 6-7 (Mohs). Color: Grey-green matrix with a white/translucent vein. Luster: Dull/earthy matrix, vitreous vein. Non-foliated, fine-grained texture.

Formation & geological history

Formed through the accumulation of fine-grained sediment in marine or fluvial environments. The vein formed later when tectonic stress created a fracture, allowing silica-rich hydrothermal fluids to precipitate quartz.

Uses & applications

Used primarily as decorative river stones, landscaping, or as garden rocks. Clastic rocks are also used in construction aggregate and road base.

Geological facts

The white line is a 'healed' fracture. Geologists use these veins to determine the history of stress and fluid movement within the Earth's crust.

Field identification & locations

Identify in the field by the distinct color contrast between the host rock and the protruding or distinct linear vein. Commonly found in riverbeds, glacial tills, and coastal beaches.