Diamond Matter is slightly bigger than Grey Matter.
Diamond Matter had Diamondhead's crystalline skin. He also had Diamondhead's spikes on his back and the back of his head.
Diamond Matter had Grey Matter's eyes and mouth.
Diamond Matter wore a uniform that was white with black cuffs on the left and black with white cuffs on the right. Diamond Matter wore the Omnitrix symbol on his chest.
Powers and Abilities
Diamond Matter had Diamondhead's ability to alter the shape of his limbs, but his strength is reduced by Grey Matter's strength. However, Grey Matter's super intelligence allowed him to shoot diamond shards with excellent precision.