Rinehart’s assets soared to $18 billion when South Korean steel miner Posco agreed to buy a 15 per cent stake in one of her iron ore mines in Western Australia. The deal was valued at $10 billion. 

Rinehard has ambitious plans to expand her iron ore business in coming years, said Forbes. If commodity prices stay firm, she could soon become the world’s richest woman, overtaking Wal-Mart owner Christy Walton, who has $24.5 billion of assets.

Her estimated fortune puts her close behind Asia's two wealthiest people, India's Mukesh Ambani who has $22.6 billion and Hong Kong property billionaire Li Ka-shing, with an estimated net worth of $22 billion.

Many of Australia’s richest individuals have seen their fortunes swell off the back of buoyant commodities prices. The total wealth of Australia’s richest 40 is $84.9 billion, up from $68.4 billion last year, according to the US magazine.