Shale
From Conservapedia
This is an old revision of this page, as edited by MikeR (Talk | contribs) at 11:32, July 17, 2008. It may differ significantly from current revision.
Shale, sometimes called Mudstone is a fine-grained sedimentary rock made from clay or mud. Shale is the most common type of sedimentary rock, and a large proportion of fossils are found in it.
Shale can be converted into slate by the application of heat and pressure, which is used in building construction, and for a number of other useful items such as chalk boards.