Australian mining billionaire Gina Rinehart has built major stakes in rare-earth and critical minerals companies alongside her iron-ore business. Philip Gostelow/Bloomberg/Getty Images Australian mining billionaire Gina Rinehart's Hancock Prospecting has invested in SpaceX's record-breaking IPO. Hancock Prospecting says it sees opportunities to work with SpaceX in critical minerals. The IPO raised more than $85 billion and pushed SpaceX's value above $2 trillion. Australian mining billionai...