A polycrystalline diamond abrasive element, particularly a cutting element, comprises a table of polycrystalline diamond bonded to a substrate, particularly a cemented carbide substrate, along a non-planar interface. The non-planar interface typically has a cruciform configuration. The polycrystalline diamond has a high wear-resistance, and has a region adjacent the working surface lean in catalysing material and a region rich in catalysing material. The region lean in catalysing material extends to a depth of 40 to 90 microns, which is much shallower than in the prior art. Notwithstanding the shallow region lean in catalysing material, the polycrystalline diamond cutters have a wear resistance, impact strength and cutter life comparable to that of prior art cutters, but requiring only 20% of the treatment times of the prior art cutters.