Ann: Mt Edon Drilling Results Confirm High Grade Rubidium, page-101

Pure comedy - so you really think they are going to mine that deposit purely for Rubidium, and not as a (very insignificant) by product like every other supplier of it does.
Your random $3500 report which you did not buy nor read, seems to infer the market for it is around 1000x the size of what every other citation does, which to me would suggest someone got their kg and tonnes mixed up.
But even if the global market for it was worth $6bn instead of $6m. Show me with some back of an envelope calcs how you think mining specifically for rubidium would work economically?
It doesn't.
Forget about this deposit.