(1) According to Abhidharma, eight kinds of spherical conglomerates of eight types of subparticles: the four element sources ('byungs-ba'i khams-bzhi) of earth, water, fire and wind subparticles and the four derivative elements ('byung-gyur bzhi) of sight, smell, taste and touch (physical sensation) subparticles. Whichever subparticle dominates determines the type of particle any of them are. Vaibhashika and Sautrantika assert the subparticles as partless, whereas the Mahayana tenet systems assert them as having directional parts. There are also sound particles and particles of the cognitive sensors. (2) The Kalachakra system asserts particles of the elemental sources: earth particles, water particles, fire particles, wind particles and space particles, each with successively less sensory qualities.
Tibetan: རྡུལ་ཕྲ་རབ། རྡུལ་ཕྲན། rdul phra-rab; rdul-phran