Mixite is a rare copper bismuth arsenate mineral with formula: BiCu6(AsO4)3(OH)6·3(H2O).

It occurs as a secondary mineral in the oxidized zones of copper deposits.

Associated minerals include: bismutite, smaltite, native bismuth, atelestite, erythrite, malachite and barite.

[2] It was discovered in 1879 near J´achymov, Czech Republic by mine engineer Anton Mixa.

[5] Mixite has also been found in Argentina,[6] Australia,[7] Austria,[8] France,[9] Germany,[10] Greece,[11] Hungary,[12] Italy,[13] Japan,[14] Mexico,[15] Namibia,[16] Poland,[17] Spain,[18] Switzerland,[19] the United Kingdom,[20] and the United States.