Gina Rinehart's Hancock Prospecting doubled profits in 2016-17 to more than A$1 billion ($1.2b) as the Roy Hill mine finally hit full tilt, iron ore prices rose and a A$190 million donation towards building a hospital in Darwin was refunded.
And that's not all that's doubled. Rinehart's personal fortune has as well, to A$21.5 billion, according to new estimates by Forbes Magazine.
Financial statements for Hancock, which is a private company, were filed on Thursday and show a 142 per cent surge in net profit from A$443 million to A$1.07 billion in the most recent financial year.
The big driver was a huge jump in mineral sales, from A$1.9 billion to A$4.5 billion, thanks mainly to the Roy Hill project in the Pilbara region of Western Australia. It hit full capacity during last financial year - later than originally expected.
"The Roy Hill project is now a contributor to Hancock's revenue and profit, and is largely responsible for the 160 per cent increase in revenue for the year," the company said in a media release.