There are several differences between these two types of grinding. Silicon carbide slurry utilizes a slowly turning cast iron wheel on which drops a "slurry" of grit. Each grit requires a different wheel or at least a lengthy cleaning period between usage of different grits to prevent cross contamination.

Diamond grinding uses a horizontal lapping machine at a much higher speed. The "grit" is supplied by diamonds electroplated to the surface of a disk. The disks are then magnetically adhered onto the wheel head. There is no need for separate machines for each grit and no worry of cross contamination. The "grit" of the diamond is locked onto the surface of the disk via the electroplating process. The only refuse created is the ground glass itself and that spins off of the disk and away. Disks are easily and quickly interchanged. Just "pop" one off the wheel and put the next one on.

Silicon carbide grinding is also a slow and arduous process. Diamond grinding can move three to for times faster than conventional silicon carbide grinding. This cuts down on processing time, strain on your wrists and back and product turnover.

Silicon carbide, as it grinds your piece, also grinds away the cast iron wheel head. This creates "grooves" in the wheel necessitating taking time out to grind down your wheel head to maintain a semblence of flatness to your work. Even then, your piece will never truly be flat on the ground surface (something required of surfaces to be glued). Diamond grinding has no such drawback. The grinding is done soley by the diamonds, which are locked into place on the disk. Provided that your wheel head is flat, the diamond surface will also be flat, therefore your pieces will be flat.

With proper usage and maintenance it's possible to consistently achieve near optical flatness from your glass with diamonds.