sedimentary
Ferruginous Sandstone
Arenite with iron oxide cement (predominantly SiO2 with Fe2O3)
AI-generated identification · may be incorrectHardness 6-7 on Mohs scale; reddish-brown to dark rusty color; dull to earthy luster; clastic texture composed of cemented sand-sized quartz grains.
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Physical properties
Hardness 6-7 on Mohs scale; reddish-brown to dark rusty color; dull to earthy luster; clastic texture composed of cemented sand-sized quartz grains.
Formation & geological history
Formed by compaction and cementation of quartz sand grains where iron oxides (hematite or goethite) precipitated from groundwater as the binding cement.
Uses & applications
Commonly quarried as a durable building stone, decorative landscaping rock, and flagstone.
Geological facts
The distinctive rusty red coloration is directly caused by minimal amounts of oxidizing iron minerals coating each individual sand grain.
Field identification & locations
Identified in the field by its sandpaper-like gritty feel and persistent reddish-brown streak; widely found in sedimentary basins and riverbeds.
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