"However, clay content is only one piece of the puzzle ... future to estimate the physical properties of fine-grained ...

Pure limestones are white or almost white, but impurities, such as clay, sand, organic remains, iron oxide, and other materials, cause them to exhibit different colors, especially on weathered ...

Sedimentary rocks close sedimentary rockSedimentary rocks ... which originates from clay. Slate is dark grey/green in colour and can be split into thin layers for use as roofing material.

The only exception to the rule is Country Tyrone which has a bit of everything - clay, basalt ... become compacted to form a new type of rock called sedimentary rock. Think of it as recycled ...