I'need to remove some internal moulds/casts of small Ammonites and Gastropods for identification purposes.
The Fossils consist of the same material as the matrix, namely Liassic mud/limestones of lower Jurassic age; they're coated with a brown pyritical stain/shell remains.
Any advice would be most welcome. I have managed to remove one or two but with not very satisfactory results.
Thanks
Trog