The electrochemical nucleation and growth of silicon on vitreous carbon and graphite are characterized. The anode is a copper:silicon alloy and the electrolyte is a molten solution of at 750°C. SEM examination of the initial stages of electrodeposition shows that the nucleation process is instantaneous and is followed by three dimensional growth. Because the nucleation is instantaneous, the initial nucleation density and the grain size of the deposited silicon can be controlled. Existing theoretical models for nucleation and their failure to model this system are also discussed.