Capital and other commitments (Details) - USD ($) $ in Thousands |
Dec. 31, 2025 |
Jun. 30, 2025 |
|---|---|---|
| Payable within One Year [Member] | ||
| Capital and other commitments [Abstract] | ||
| Water rights | $ 1,594 | $ 1,336 |
| Non-cancellable lease commitments | 190 | 261 |
| Exploration and evaluation expenditure commitments | 0 | 317 |
| Capital commitments | 1,784 | 1,914 |
| Payable After One Year but not Later than Five Years [Member] | ||
| Capital and other commitments [Abstract] | ||
| Water rights | 5,392 | 4,971 |
| Non-cancellable lease commitments | 163 | 288 |
| Exploration and evaluation expenditure commitments | 0 | 317 |
| Capital commitments | 5,555 | 5,576 |
| Payable Later than Five Years [Member] | ||
| Capital and other commitments [Abstract] | ||
| Water rights | 9,143 | 9,116 |
| Non-cancellable lease commitments | 0 | 0 |
| Exploration and evaluation expenditure commitments | 0 | 0 |
| Capital commitments | $ 9,143 | $ 9,116 |