Data for: Elemental and mineralogical constraints on environmental contamination from slag at Gulf Creek copper mine

These are xrdml files able to be opened and analysed by most major manufacturer's XRD software. Bulk powder mineralogy was examined using X-ray diffractometry (XRD). Slags and salt efflorescences were crushed and milled in a tungsten carbide ball mill or agate mortar and pestle respectively. Preparation equipment was cleaned with a quartz sand blank and wiped with ethanol between samples. Powders were mounted on silicon crystal low background holders. Diffractograms were collected from 5° to 90° 2θ using a Malvern Panalytical Aeris diffractometer with PIXcel1D detector, operated at 40 kV, 15 mA with CuKα radiation at a slew rate of 6° 2θ min-1. Diffractograms were analysed using PANalytical HighScore+ software v. 2.2.1 with the 2015 International Centre for Diffraction Data Powder Diffraction File 2 inorganic mineralogical database and the FIZ Karlsruhe GmbH Inorganic Crystal Structure Database. Detection limits depend on crystallinity but were typically 0.1 – 2 wt%.