I think you're mixing up a bunch of different materials. Sodium is too reactive to isolate with regular smelting and is usually obtained through electrolysis (19th century tech), and uranium ore is just a slightly toxic rock that people get might possibly be getting sick from mining (due to radon gas). Actual radioactive uranium (U-235) requires the use of centrifuges and chemical engineering to isolate (20th century tech). Lodestones are natural rocks that have existed before human civilization. (prehistorical tech)
If you clarified your question to one of these three time periods it might be easier to answer.
/u/hillsonghoods talks about the attitudes of historical peoples towards magnets in this answer, and they also have a good answer in the FAQ about electricity that could help you with your question.
For uranium, here's a recent AskHistorians question about radiation.