Mudstone

This is a short overview. For the background — history, value over time and notable mines — see Mudstone →

A fine-grained sedimentary rock of consolidated clay and silt, distinguished from shale by not splitting along its bedding. Rarely quarried for its own sake — it is too weak for building and too soft for roadstone — it is nonetheless the raw material of most British brickmaking, and the parent rock of slate and fireclay. In this archive it appears mostly as the rock a quarry is cut in or a mine is driven through.