One of the most well-regarded natural whetstones is the yellow-gray "Belgian Coticule", which has been legendary for the edge it can give to blades since Roman times, and has been quarried for centuries from the Ardennes. The slightly coarser and more plentiful "Belgian Blue" whetstone is found naturally with the yellow coticule in adjacent strata; hence two-sided whetstones are available, with a naturally occurring seam between the yellow and blue layers. These are highly prized for their natural elegance and beauty, and for providing both a fast-cutting surface for establishing a bevel and a finer surface for refining it. This stone is considered one of the finest for sharpening straight razors.[citation needed] 

Low Grit Stones: A sharpening stone with grit number less than a 1000 is generally used for knives and tools that are damaged. If your blade has any nicks or chips in the blade, the stones will take care of them in a jiffy! They usually have a coarse side for nicks and chips, with the other side for general sharpening. Even if the knife’s edge has become totally blunt, the stone will re-sharpen it perfectly.
I can personally verify that this will get your knives very sharp. I will spare you all the gory details, but the picture is of the instructions the ER sent me home with after stopping the bleeding and patching me up. I have to say, that’s not what I had in mind regarding “Thanksgiving tips”. So: not only will knives slide easily through spinach, but they will go through finger and fingernail like a hot knife through butter after being sharpened by this whetstone. Very clean, straight cut. Impressive, really. Just take it slow and don’t be a moron like me.
Your task as a sharpener is to remove that fatigued metal and expose the steel underneath, the fresh strong steel and bring side A and B of the knife together at the Apex precisely, sounds easy doesn’t it? Like peeling a layer off and having a fresh start, over and over. Of course there is much more to it than this but in very basic terms, you want the abrasive properties of the water stone to abrade the fatigued metal away, like an eraser.

JapaneseChefsKnife.Com (JCK, Established in 2003) is the direct internet sales division of The Kencrest Corporation. We supply a wide range of top quality Japanese Chef's knives at lower than Japanese Retail Prices direct from Seki City; the Japanese cutlery capital where fine knives are produced using over 800 years of Samurai sword-making tradition and history.
Once you've sharpened one side, you need to flip over, but don't swap the hand gripping the blade – think of it a bit like going backhand with a tennis racket (see above). Lead with the heel this time, rather then with the blade, but repeat the process in three parts. After five strokes on each third of the blade, it's time to check your knife. It's not an exact science, and it all depends on how blunt your blade was to start with (mine was very blunt indeed). But if you sharpen fairly regularly, it should just take a few strokes. 
Sharpening is really two processes: Grinding and honing. Grinding is simply the removal of metal. Honing is a precision abrasion process in which a relatively small amount of material is removed from the surface by the means of abrasive stones. Once you have the right shape, usually using a more aggressive grit, you then switch to a finer grit to hone the edge.
I recommend it as a lightweight alternative to larger stone for smaller knives. Leather necklace is comfortable and seems strong. I conditioned it for suppleness and swim with it on tightened as a choker. Stone is small, dog-tag size. I use it with water. Functional for small folder knives and multi-tools. Not useful for large fixed blades, since you can't make a long stroke. Small to grip. I use double-sided tape on one side to keep it in place on a flat rock. Not sure of grit, seems like around 1000. It took a while, but i got my old boy scout knife sharp. 
×