The diamonds are called lozenges - just get some bloody photographs.

Bell pits don't have spoil heaps, that's one of their characteristics, Just because something is marked on the map as something doesn't mean that's what it is - it means that what they thought it was. If a person is digging coal it must have an enduse and it's heavy stuff. So there will be a firm track leading somewhere - no track, no coal mine. Find me a coalmine that has no roadway leading to it - you can't, it's impossible - therefore it's not a spoil heap. You don't get round spoil heaps (without overhead hoppers). The coal pits on the moor were at the other end, against Georges Lane, near the place known as Hole Bottom, shown on the old map as Tileworks - there's plenty of tracks there.