A process for the formation of particles of a target material is disclosed, comprising: (i) introducing the target material into a particle formation vessel, and forming a continuous liquid surface of the target material in the particle formation vessel, and an interface between said liquid surface of the target material and additional gaseous contents of said particle formation vessel; (ii) introducing a stream of cryogenic material including solid particles of cryogenic material into the particle formation vessel and into contact with the target material in a liquid state below the continuous liquid surface; (iii) allowing rapid volumetric expansion of the cryogenic material into a gaseous state while in contact with the target material in a liquid state, and release of the expanded gaseous cryogenic material through the continuous liquid surface, and forming liquid droplet particles of the target material; and (iv) collecting the formed particles of the target material.