XAFS and μ‐XAFS spectra were collected at the Cu K‐edge for seven chrysocolla samples (Peru, USA, and Congo). The results suggest that that the local structure around Cu is similar to that in Cu(OH)2 (spertiniite). Cu‐L3 STXM imaging and spectroscopy confirm that the chrysocolla samples examined here consist of mesoscopic Cu(II)‐rich domains surrounded by Si‐rich domains (in agreement with results from infra‐red spectroscopy). Hence, we suggest that chrysocolla, which is generally considered to be orthorhombic with composition (Cu,Al)2H2Si2O5(OH)4⋅nH2O, is in actually a mesoscopic assemblage composed dominantly of spertiniite (Cu(OH)2), water and amorphous silica (SiO2).

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