Old red sandstone microscope slide exhibiting the well sorted nature of this ancient sedimentary rock. The grains are very fine but iron oxide rims can be distinguished around quartz clasts in PPL view. The Old Red Sandstone describes a suite of sedimentary rocks deposited in a variety of environments during the Devonian but extending back into the late Silurian and on into the earliest part of the Carboniferous. It is dominated by alluvial sediments with conglomerates at its base, and progresses to a combination of aeolian, lakes and river sediments. The familiar red colour of the rocks is from the presence of Iron Oxide. These slides are made from our own stock of Lower Devonian Old Red Sandstone which was collected from Gloucestershire. The section is made to 30 microns thickness and the glass is 46 x 27 mm in size with a cover slip. Supplied in a protective card sleeve with a label, ideal for microscopy.