i mine platinum, it is very profitable 12 tria each and it doesnt take long to find 10 pieces which means you could get rich very fast 10x12 = 120 that means a pick axe for every 10 ore and you have 20 left over (i can do it very quick and i have mining level 0!)
and im not going to tell you where you can mine it but the hint you got already is more than i got when i found it