There are generally three type of whetstones such as a rough whetstone (#120 - #600), a medium whetstone (#800 - #2000), and a finishing whetstone (#3000 - #6000).
Among the three types of whetstone, this is the grainiest, ranging from #120 - #600. Use it when repairing a large edge that may include chips or cracks.
Medium whetstones are for use on a daily basis, such as when the sharpness has declined and cutting has changed noticeably. The weight of these stones range from #800 - #2000. Use it also for a middle sharpening point after using rough grinding stone. This will decrease the grinding pattern on the metal after a rough stone.
A finishing whetstone is used when creating minor adjustments to the cutting edge. Since the polishing power is weak, use it after grinding with a medium whetstone. It is the smoothest among grinding stones and ranges from #3000 - #6000.
A natural grinding stone is a grinding stone made by cutting stones present in nature. There are various whetstones depending on production area. Because it is a natural whetstone, it may be broken.
Please note, because this is natural, you can not exchange even if it is broken as they may have inherent weaknesses.
Since artificial diamond is used for the abrasive material, harder ceramic knives are also able to be ground. The material is very hard and can keep a flat state over multiple knife sharpening.
If you use diamond whetstone, the grinding stone itself may slip and it can be difficult to sharpen, possibly causing injuries. Because the diamond grinding stone is sharp, we recommend that you have a case/base that can be fixed so that you can work safely. These whetstones will last longer than natural or ceramic but also cost more than their counterparts.
The ceramic whetstones are an artificial grinding stone with high hardness. It is high in polishing power and it is characterized by quickly grinding. Although it is hard, the grinding force is also stronger than the conventional grinding stone.
As these are made of softer materials than Natural or Diamond, it will wear down faster. In particular, it can lose it's flat surface and may need to be resurfaced.