Australia's richest person Gina Rinehart has eclipsed Wal-Mart heiress Christy Walton to become the world's wealthiest woman, according to an annual index by Business Review Weekly.
In March, Forbes placed Walton and her family's net worth at US$25.3 billion, while Rinehart's fortune stood at US$18 billion.
BRW rich list editor Andrew Heathcote said mining magnate Rinehart had almost tripled her wealth in 12 months as commodity prices rose and she pulled off two deals in iron ore and coal.