STONE JB6 6X2X1|Norton’s combination grit benchstones are available in two different combinations. The crystolon combination (dark gray in color) features a coarse and fine grit sharp-cutting silicon surface. It can be used for general sharpening when the speed of sharpening is more important than the fineness of the cutting edges. The India combination (orange/brown in color) features a coarse and fine grit aluminum oxide abrasive surface for keen, long-lasting edges on quality tools. Either combination can be used on chip breakers, draw knives, scrapers, wood chisels and plane blades.