Australian mining billionaire Gina Rinehart has built major stakes in rare-earth and critical minerals companies alongside her iron-ore business.

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Australian mining billionaire Gina Rinehart has made a major bet on Elon Musk's SpaceX that could lead to more than just a financial return.Rinehart — Australia's richest person with a fortune estimated at $38.4 billion by the Bloomberg Billionaires Index — invested through Hancock Prospecting, her privately held mining and agriculture company.Hancock Prospecting said Monday that it was allocated shares in SpaceX's initial public offering. The company did not disclose the size of its "significant investment," though The Wall Street Journal reported that the stake was worth more than $1 billion."In the future, we also see the possibility of mutually beneficial arrangements between SpaceX and Hancock Prospecting's significant critical minerals investments, as demand grows for the materials and infrastructure needed to support advanced technology," said Garry Korte, the CEO of Hancock Prospecting, in a statement. He described the SpaceX share allocation as "generous."The comments point to potential opportunities between SpaceX and Rinehart's growing portfolio of critical minerals investments.SpaceX has identified asteroid mining as a potential future opportunity, while NASA is supporting efforts to develop a commercial economy on and around the moon that could eventually include resource extraction.Those ambitions could increase demand for the kinds of critical minerals that Rinehart has spent years investing in.