well that second stone is a translucent ark which is the finest ark you can buy its a finishing stone you'll have to use a light touch and round a 200 lap count for finishing make sure your bevel is set and very sharp that will speed the process up before you use the ark dont worry about lapping the ark its a very hard stone( but still check for flatness) you can use water or oil . oil would be best the stone is nonporous so it wont absorb water or oil