Abstract: A composition for chemical-mechanical planarization comprises periodic acid and an abrasive present in a combined amount sufficient to planarize a substrate surface having a feature thereon comprising a noble metal, noble metal alloy, noble metal oxide, or any combination thereof. In one embodiment, the periodic acid is present in an amount in a range of from about 0.05 to about 0.3 moles/kilogram, and the abrasive is present in an amount in a range of from about 0.2 to about 6 weight percent. In another embodiment, the composition further comprises a pH-adjusting agent present in an amount sufficient to cause the pH of the composition to be in a range of from about pH 5 to about pH 10, or of from about pH 1 to about pH 4.