What is Puddingstone?
[[File:Conglomerate rock called puddingstone. - geograph.org.uk - 480555.jpg|thumb|right|230px|Puddingstone with large pebbles]] [[File:Puddingstone outcrop on Coppet Hill - geograph.org.uk - 465829.jpg|thumb|right|230px|Puddingstone outcrop on Coppet Hill Puddingstone is common in this area of the [[Wye]] valley from here towards [[Monmouth]]. Some forms were 'mined' and shaped into [[millstone]]s for their abrasive qualities.]] '''Puddingstone''' is a kind of [[sedimentary rock]]. It is formed when pebbles, perhaps from a [[shingle beach]], are [[cement]]ed together by [[silica]] coming out of [[solution]]. The rock which forms is extremely hard and resistant to wear. It is used for grindstones and building. The pebbles are usually made of [[flint]], and both they and the [[Matrix (geology)|matrix]] are made of silica. {{science-stub}} [[Category:Sedimentary rocks]]