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]
Some of the videos I watched suggested soaking the stone for 12-15 minutes prior to use. One suggested using vegetable oil on the surface versus water/soaking (I used water and presoaking it for 15-minutes). So instead of a simple 'out-of-the-box-and-use' approach, it required a bit of research before sharpening a knife. Otherwise I would have given this product a 5-star rating.

Keep your knife razor-sharp with a high-quality sharpening stone. We offer a wide variety of sharpening stones, such as Arkansas stone, Diamond stone, Bench stone, Water stone and more. Whether you own a pocket knife, a hunting knife or a kitchen knife, a sharpening stone is essential for preventing your blade from becoming dull.  Most of our sharpening stones are lightweight and portable, so you can use them at home or take them with you wherever you go.
A sharpening stone is made of particles of abrasive material that are sintered or bonded together. The blade is moved across the stone and the steel is worn away, which creates the edge. However, at the same time, the stone is also worn away to reveal new, coarse particles. As a general rule, the softer the stone, the more rapidly it will wear and will be more aggressive in use. Harder stones don’t wear as quickly.
I'm a novice knife sharpener. I've had to unlearn what my grandpa taught me in order to use these. So far, I've had decent but mixed results. I've switched to my cheap 200/400-ish cheap tool stone from harbor freight for cutting a bevel when the blade has either been damaged or did not have a proper bevel. The 400/1000 grit stone in this kit is soft. Very soft. I have bowled it out several times. It makes keeping a steady angle difficult. But these stones at this price point are meant for learning, and for that they serve their purpose.
One thing about this stone is that it is very "thirsty." I had a cup of water close by just to add a little water periodically when it felt like it was scraping a little too aggressively. Also, be sure to do as the instructions say and use different parts of the sharpening surface. I wasn't paying attention the first few minutes, and apparently I would end each sharpening pass in the exact same spot, creating a very very small notch on the edge of the stone. So I turned the stone around and made sure to vary the ending spot, and it seemed to buff out that little notch very quickly. My knife is now incredibly sharp--it seems to glide through material rather than "cut" it. I know some people would continue to go even higher with the grit, but for my purposes this whetstone is just perfect. I'll be tackling the kitchen knives next!
This is my first time ordering from hayneedle, but you came thru with flying colors. I was so happy to see the delivery come so quick as stated. It was just as i hoped it would be, i now have my whetstone sharpening stone, to really get my kitchen knives as sharp as i can get them. This to me is the best way to sharpen a knife, it takes patience but the reward is worth it. Thanks Hayneedle you rock!!! Ray D.
Clamp-style sharpening tools use a clamp with several holes with predefined angles. The stone is mounted on a rod and is pulled through these holes, so that the angle remains consistent. Another system is the crock stick setup, where two sticks are put into a plastic or wooden base to form a V shape. When the knife is pulled up the V, the angle is held so long as the blade is held perpendicular to the base. Several cutlery manufacturers now offer electric knife sharpeners with multiple stages with at least one grinding stage. These electric sharpeners are typically used in the kitchen but have the ability to sharpen blades such as pocket or tactical knives. The main benefit of using an electric sharpener is speed with many models that can complete the sharpening process in one to two minutes. The disadvantage is that the sharpening angle is fixed so some specialized knives, like a Japanese style Santoku, may need additional attention to sharpen to the ideal angle.
We’ve shown you how to keep knives sharp before, and even discussed why water stones are best, but this crash course is quick, fast, and gets to the point. In most cases the most the average person at home can do is either hone their blade with a honing steel, which straightens and lines up the blade’s edge, but it doesn’t sharpen it. Alternatively you could run it through a handheld or electronic sharpener, but depending on the model you use it can do more harm than good.