These notes cover the species a British collection is built on: fluorite at hardness 4 with perfect octahedral cleavage, pyromorphite at 3.5-4 in hoppered green prisms, cassiterite at 6-7 and a density near 7, and scorodite, a hydrated arsenate common as a crust and rare as a gemmy crystal.
- FluoriteThe most collected British mineral, and the one where locality does most of the work in setting a price.
- PyromorphiteA lead phosphate that produces some of Britain's most distinctive specimens, including the barrel-shaped campylite of the Caldbeck Fells.
- CassiteriteThe mineral that funded Cornwall. Heavy, hard, and at its best forming the elbow twins collectors chase.
- ScoroditeCommon as a dull crust, rare as a transparent blue crystal. The 2006 Hemerdon dig produced the latter, and it is what put that locality on collectors' maps.