v3.25.2
Fair value measurement (Details) - USD ($)
$ in Thousands
Jun. 30, 2025
Dec. 31, 2024
Fair value measurement    
Financial assets, carrying value $ 122,551 $ 183,191
Financial assets, fair value 122,551 183,191
Financial liability 696,828 685,757
Financial liabilities, fair value 718,692 697,092
Financial liabilities measured at amortised cost    
Fair value measurement    
Financial liability 454,987 464,802
Financial liabilities, fair value 476,851 476,137
Financial liabilities at fair value through profit or loss    
Fair value measurement    
Financial liability 241,841 220,955
Financial liabilities, fair value 241,841 220,955
Trade and other payables | Financial liabilities measured at amortised cost    
Fair value measurement    
Financial liability 79,742 51,050
Financial liabilities, fair value 79,742 51,050
Lease liability | Financial liabilities measured at amortised cost    
Fair value measurement    
Financial liability 7,444 10,233
Financial liabilities, fair value 7,444 10,233
Loans and borrowings | Financial liabilities measured at amortised cost | Level 2    
Fair value measurement    
Financial liability 367,576 403,191
Financial liabilities, fair value 389,440 414,526
Other financial liabilities (excluding contingent consideration) | Financial liabilities measured at amortised cost    
Fair value measurement    
Financial liability 225 328
Financial liabilities, fair value 225 328
Royalty deed | Financial liabilities at fair value through profit or loss | Level 3    
Fair value measurement    
Financial liability 46,515 47,661
Financial liabilities, fair value 46,515 47,661
Contingent copper consideration | Financial liabilities at fair value through profit or loss | Level 3    
Fair value measurement    
Financial liability 119,590 94,050
Financial liabilities, fair value 119,590 94,050
Mezz Warrants | Financial liabilities at fair value through profit or loss | Level 3    
Fair value measurement    
Financial liability 14,835 11,066
Financial liabilities, fair value 14,835 11,066
Mezzanine debt facility embedded derivative | Financial liabilities at fair value through profit or loss | Level 2    
Fair value measurement    
Financial liability   34,713
Financial liabilities, fair value   34,713
Silver stream embedded derivative | Financial liabilities at fair value through profit or loss | Level 3    
Fair value measurement    
Financial liability 34,112 16,163
Financial liabilities, fair value 34,112 16,163
Copper stream embedded derivative | Financial liabilities at fair value through profit or loss | Level 3    
Fair value measurement    
Financial liability 8,081 5,182
Financial liabilities, fair value 8,081 5,182
Commodity swap liability | Financial liabilities at fair value through profit or loss | Level 2    
Fair value measurement    
Financial liability 18,708 12,120
Financial liabilities, fair value 18,708 12,120
Cash and cash equivalents | Fair value through profit or loss | Level 1    
Fair value measurement    
Financial assets, carrying value 102,109 171,897
Financial assets, fair value 102,109 171,897
Investments | Fair value through profit or loss | Level 1    
Fair value measurement    
Financial assets, carrying value 5,538 3,984
Financial assets, fair value 5,538 3,984
Trade and other receivables | Fair value through profit or loss | Level 1    
Fair value measurement    
Financial assets, carrying value 14,904 7,310
Financial assets, fair value $ 14,904 $ 7,310