The convex edge acts as a wedge

from a particular part of a horsehide

it is much clearer and more informative

This is normal for natural stones and not treated as a defect

atoma diamond for kme Grit:600 The convex edge acts asAtoma Diamonds are used for sharpening knives on KME knife sharpeners. KME format stones of Atoma are made by Jende Industries. Atoma Diamond consists of a diamond bearing nickel plate mounted on the high quality aluminum blank. In contrast to regular coated diamonds, all diamond particles in Atoma are gathered into cluster pattern. This approach gives Atoma diamonds higher sharpening performance in comparison with any other diamonds.