Thermally stable diamond constructions comprise a diamond body having a plurality of bonded diamond crystals and interstitial regions disposed among the crystals. A metallic substrate is attached to the body. The body includes a first region substantially free of a catalyst material that extends a partial depth from a surface into the body, and a second region that includes the catalyst material. The body can include natural diamond grains and/or a blend of natural and synthetic diamond grains, and is treated to form the first region. Before treatment, a portion of the body to be treated is finished to an approximate final dimension so that the depth of the first region of the finished product is substantially the same as when treated. During treatment, catalyst materials as well as non-catalyst metallic materials are removed from the diamond body to provide a further enhanced degree of thermal stability.