... ''x2'' Green Silicon Carbide Rubbing Brick Applicable for grinding sandstone,marble,and other soft metal materials. 6''x2''x2'' Green Silicon Carbide Rubbing BrickA very ... ,soft metal materials,etc.Made up of GC (short for Green Sillcon Carbide),an abrasive material softer than Diamond & Aluminum Oxide. Size ... /T,L/C,Wetern Union,etc. 6''x2''x2'' Green Silicon Carbide(GC) Rubbing Brick for Stone