The present invention provides methods of forming high quality diamond bodies under high pressure, and the diamond bodies produced by such methods. In one aspect, a method is provided for growing a diamond body, including providing a non-particulate silicon carbide (SiC) mass having a pre-designed shape, placing the SiC mass under high pressure in association with a molten catalyst and a carbon source, and maintaining the SiC mass under high pressure to form a substantially monocrystalline diamond body. The diamond body may be formed across substantially all of the SiC mass having surface area exposed to the molten catalyst. As such, the diamond body may conform to the shape of the exposed surface area of the SiC mass.