Sunday Stone - A Coal Mine Work Log?

This posting is not about a fossil but an interesting artifact I saw on display at the British Natural History Museum in London, England. It is called the Sunday Stone that formed in South Shields a Tyneside coal mine in the 1800s. A water trough in the mine used to relieve the thirst of work animals had the white mineral barium sulphate settle while container also had black coal dust accumulate during mining activity. It resulted in a banding and provides a visual representation of when the mining was going on (dark lines) and the white areas when it was Sunday (a day of rest) and larger gaps holidays or mine is idle.

Link to image of another one in the Oxford University collection:
https://www.geolsoc.org.uk/Geoscientist/Archive/August-2008/Never-on-a-Sunday

More information about Sunday Stones can be found in this book:
Curiosities of Natural History: Second Series by Francis T. Buckland 1903
https://archive.org/details/curiositiesnatu09buckgoog

Amaltheus margaritatus Ammonite Fossil

This image is of the Amaltheus margaritatus ammonite fossil. It was found in Middle Lias from Eype of Dorset England. Creature is from the Jurassic Period. Fossil on display at the Lyme Regis Museum in England as of August 2016.

Learn more at www.lymeregismuseum.co.uk

Cluster of Orthotetes Brachiopod Fossils

Fossil plate was found in the Edwardsville Formation of Floyd County, Indiana, USA. The fossils date to the lower Carboniferous (Mississippian) Period. The brachiopods on the plate appear to be Orthotetes keokuk. It is somewhat rare to find so many clustered together.

Thanks to Kenny for the image.