Abstract
The present study deals with polishing machining of diamond for jewelry using developed automatic polishing machine that can cut diamond to have 58 facets in a brilliant cutting which has been hardly achieved by a conventional manually operating polishing machine. Upon the 3-dimensional Sarin M/C test and analysis on the machined diamond by the developed automatic polishing machine its proportion and finishing turned out to be better than the machined diamond by the conventional manually operating polishing machine.