Fire Opal from
UK | |
| Phillips, William (1823) An Elementary Introduction to Mineralogy (3rd ed.) |
| Hogg, Thomas (1825) A Manual of Mineralogy - In which is shown how much Cornwall contributes to the illustration of the science. W. Polybank High Cross, Truro. |
| J.Ralph collection |
| Carne, J. (1822) On the relative age of the veins of Cornwall. Transactions of the Royal Geological Society of Cornwall, 2. 49-128 |
Botallack Mine, Botallack, St Just, Cornwall, England, UK