We tend to recommend natural Japanese water stones only to experienced users who are thoroughly familiar with the synthetic Japanese sharpening stones. Natural stones are not to everybody’s taste and there are inevitably many uncertainties with regard to their grit grade, which cannot be determined exactly, their hardness and their suitability for certain types of steel.

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]
There are no lengthy explanations needed to describe the Lansky 8” Ceramic Sharp Stick sharpener. It’s an old-fashioned device comprised of a hardwood handle and ceramic sharpening rod. That’s it. Sure it’s not going to create an absolutely picture perfect edge down to the last micron but it will keep your knives really sharp and do so for next to nothing.
Vielsalm Coticule on the other hand generally occurs in much more narrow layers sandwiched between the slate layer and the Belgian Blue layer and thus, it is both less plentiful and more expensive than Belgian Blue stone. Also, Coticule is divided into different grades and sometimes displays blemishes on the surface due to its proximity to the slate layer. Furthermore, it is somewhat harder than Belgium Blue stone and, due to its brittleness, it is bonded to a substrate layer of hard slate prior to sale to prevent the stone from breaking during use.
The smaller the angle between the blade and stone, the sharper the knife will be, but the less side force is needed to bend the edge over or chip it off. The angle between the blade and the stone is the edge angle – the angle from the vertical to one of the knife edges, and equals the angle at which the blade is held. The total angle from one side to the other is called the included angle – on a symmetric double-ground edge (a wedge shape), the angle from one edge to the other is thus twice the edge angle. Typical edge angles are about 20° (making the included angle 40° on a double-ground edge).[1] The edge angle for very sharp knives can be as little as 10 degrees (for a 20° included angle). Knives that require a tough edge (such as those that chop) may sharpen at 25° or more.

3. Place the knife blade flat on the stone and raise it to a 10 to 15 degree angle. The key to knife sharpening is maintaining a constant angle. Different knives require different sharpening angles. For a pocket knife, shoot for a 10 to 15 degree angle. This will give you an edge that’s sharp enough for most daily needs, but not sharp enough to perform heart surgery.  Keeping a constant angle by hand takes a lot of practice. If you’re having difficulty, you might consider investing in a sharpening guide. It takes all the guess work out of maintaining the needed angle. They cost about $10.

High Grit Stones: These are also known as finishing stones with the number range going up to 8000, and give you a super refined edge.  They work great with Western knives as they cutting edge resembles a “U” as opposed to a “V”. If you are using your knife to cut meat, then you can happily stop at 4000 or 6000 grit. If you are only using it for vegetables or fruit go all the way to the 8000.