The movements in the iron ore royalty interest during the year ended December 31, 2024 were as follows: | | | | | | | | | | | | | | | | | | | | Opening | | | | Ending | Costs | | balance | | Additions | | balance | Iron ore royalty interest | | $ | 218,203 | | $ | — | | $ | 218,203 |
| | | | | | | | | | | | Opening | | | | Ending | Accumulated depreciation | | balance | | Additions | | balance | Iron ore royalty interest | | $ | 21,569 | | $ | 4,492 | | $ | 26,061 | Net book value | | $ | 196,634 | | | | | $ | 192,142 |
The movements in the iron ore royalty interest during the year ended December 31, 2023 were as follows: | | | | | | | | | | | | | | | | | | | | Opening | | | | Ending | Costs | | balance | | Additions | | balance | Iron ore royalty interest | | $ | 218,203 | | $ | — | | $ | 218,203 |
| | | | | | | | | | | | | | | | | | | | Opening | | | | Ending | Accumulated depreciation | | balance | | Additions | | balance | Iron ore royalty interest | | $ | 16,401 | | $ | 5,168 | | $ | 21,569 | Net book value | | $ | 201,802 | | | | | $ | 196,634 |
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