Sigma Power Ceramic stones are made of aluminum oxide

screw clamps

During break-in period (no lapping)

The difference is we keep the names of the original sharpening stones in the names of the finished products

arkansas black stone kmex Sigma Power Ceramic stones areDan's Whetstone Black Arkansas sharpening stones are used for finish sharpening knives on KME or Hapstone knife sharpeners. Arkansas stones are made of novaculite, a naturally abrasive material of high density. Arkansas stones are mined in the Ouachita Mountains in the state of Arkansas in the United States. Arkansas stones consist of silica, but unlike synthetic abrasives, do not consist of individual abrasive grains of the same size. Arkansas quartz