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This paper presents the assessment of three spectroscopic techniques, i.e., Raman spectroscopy (RS), ultraviolet fluorescence (UVF) spectroscopy, and energy-dispersive X-ray diffraction (ED-XRD), for measuring calcite (CaCO3) concentration in copper ore. The results for the three methods are compared in terms of their correlation coefficient R2 and prediction error (root-mean-square error of prediction, RMSEP). These approaches substantially shorten the measurement time with respect to current laboratory procedures from 300 min down to 1,15, and 9 min for RS, ED-XRD, and UVF, respectively, while preserving a good accuracy level (RMSEP <; 0.577). Prediction models were calibrated and validated for the three techniques, using the correlation coefficients Rc2 and Rv2, the error of prediction (RMSEP), and the error of calibration (root-mean-square error of calibration, RMSEC). Rv2 values of 0.90,0.88, and 0.94 were obtained for the RS, UVF, and ED-XRD models, respectively. The calibration and validation were performed for calcite concentrations ranging from 2.9% to 10.7%, and although the ED-XRD model performed slightly better than its RS counterpart, the time taken by the latter is significantly shorter than that by the other two, representing a good candidate for online estimation of calcite concentration.