sedimentary

Quartz-Veined Mudstone

Argillaceous Mudstone with Quartz Veining

AI-generated identification · may be incorrect

Hardness: 3-4 (matrix), 7 (vein). Color: Reddish-brown (iron oxide) with white vein. Luster: Dull/Earthy matrix, Vitreous vein. Crystal structure: Microcrystalline. Cleavage: None.

Hardness: 3-4 (matrix), 7 (vein)
Color: Reddish-brown (iron oxide) with white vein
Luster: Dull/Earthy matrix, Vitreous vein

Identified May 21, 2026More sedimentary →

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Physical properties

Hardness: 3-4 (matrix), 7 (vein). Color: Reddish-brown (iron oxide) with white vein. Luster: Dull/Earthy matrix, Vitreous vein. Crystal structure: Microcrystalline. Cleavage: None.

Formation & geological history

Formed from the lithification of silt and clay particles (Proterozoic to Paleozoic age). The white vein formed later via hydrothermal activity where silica-rich fluids filled fractures in the rock.

Uses & applications

Primarily used as decorative landscaping rock, aggregate for construction, or as an educational piece to demonstrate geologic fracturing and mineralization.

Geological facts

The reddish hue is caused by the oxidation of iron minerals (hematite) within the sediment, indicating it formed in an oxygen-rich environment.

Field identification & locations

Identify in the field by the contrast between the soft, fine-grained reddish matrix and the hard, crystalline white vein. Commonly found in riverbeds and glacial deposits in the Great Lakes region.