Before leaving the cavern, Lex toured the whole place one more time to see if he missed anything. The strange, unknown ore in this place made it so that his spirit sense was unreliable which is why he needed to see everything for himself.
The process revealed quite a few more warehouses where creatures were experimented on, as well as a small, makeshift home which once again indicated that whoever was visiting was clearly not humanoid.
Lex grabbed one of the loose ore pieces and brought it back with him. It made sense that Lex had been unable to recognise it for he wasn't necessarily an expert in metal ores, but there was surely someone in the universe who would recognise it. Its features to completely hide things from detection was incredibly useful. If nothing else, Geeves could make a great suit out of it.
