Ultrahard composite constructions comprise a plurality of first phases
dispersed within a matrix second phase, wherein each can comprise an
ultrahard material including PCD, PcBN, and mixtures thereof. The
constructions are formed from a plurality of granules that are combined
and sintered at HP/HT conditions. The granules include a core surrounded
by a shell and both are formed from an ultrahard material or precursor
comprising an ultrahard constituent for forming the ultrahard material.
When sintered, the cores form the plurality of first phases, and the
shells form at least a portion of the second phase. The ultrahard
material used to form the granule core may have an amount of ultrahard
constituent different from that used to form the granule shell to provide
desired different properties. The ultrahard constituent in the granule
core and shell can have approximately the same particle size.