A hard Carboniferous sandstone from County Durahm. Supplied in a card tray with a label.
Ganister is a hard, fine grained , silica cemented sandstone. It is commonly, although not exclusively, found as seat earths below Carboniferous Coal Measure deposits & hence may contain root fossils. The name Ganister seems to have arisen in Yorkshire & Derbyshire where it was the local miners' & quarrymens' name for roadstone. It was particularly important around Sheffield where it was mined extensively to be used as a refractory liner for coke ovens & furnaces for the steel industry. Sheffield Ganister or Blue Ganister became the type example for this lithology. These particular specimens come from County Durham. They are supplied in labelled card trays.