sedimentary

Quartz Vein in Siltstone

Siltstone with Quartz (SiO2) inclusion

AI-generated identification · may be incorrect

Hardness: 7 (Quartz) / 3-4 (Siltstone); Color: Dark grey and milky white; Luster: Dull/Earthy (matrix) and Vitreous (quartz); Structure: Fine-grained clastic matrix with crystalline vein.

Hardness: 7 (Quartz) / 3-4 (Siltstone)
Color: Dark grey and milky white
Luster: Dull/Earthy (matrix) and Vitreous (quartz)

Identified June 17, 2026More sedimentary →

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Physical properties

Hardness: 7 (Quartz) / 3-4 (Siltstone); Color: Dark grey and milky white; Luster: Dull/Earthy (matrix) and Vitreous (quartz); Structure: Fine-grained clastic matrix with crystalline vein.

Formation & geological history

Formed through the accumulation of silt-sized particles in aqueous environments, with a later hydrothermal event where silica-rich fluids filled fractures to form the quartz vein.

Uses & applications

Primarily used as decorative garden stones, educational specimens for geology, or low-cost aggregate in construction.

Geological facts

The sharp contrast between the light quartz and dark host rock is a classic example of hydrothermal activity within sedimentary layers, demonstrating how minerals can travel through solid rock via cracks.

Field identification & locations

Identify by its dual texture: a smooth, fine-grained dark base and a hard, crystalline white protrusion. Common in riverbeds and mountainous erosion zones.