Aluminum-Oxide oil stones are very popular man-made sharpening stones produced by an abrasives company called Norton and which are commonly called India Stones. Generally less expensive than Arkansas stones (aka Novaculite), these stones are graded coarse, medium, and fine and are designed for fast cutting. Yet, when the fine grit is used, they can also produce a relatively fine edge. Also, because India Oil Stones are both softer and coarser than Arkansas Stones, they are commonly used in conjunction with Novaculite to cut the initial edge bevels or, repair extremely dull or damaged edges before refining and polishing the bevel with an Arkansas Stone.
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.

Method 1: Use an Electric Sharpener. Quality electric sharpeners are an option, but I strongly discourage their use. First off, they remove a tremendous amount of material from your edge. Sharpen your knife a dozen times, and you've lost a good half-centimeter of width, throwing it off balance, and rendering any blade with a bolster (i.e. most high-end forged blades) useless. Secondly, even the best models provide only an adequate edge. If you don't mind replacing your knives every few years and are happy with the edge they give you, they'll do the trick. But a much better choice is to...

Manufacturer contacted and sent a new one for replacement. Great customer service but replacement item was nicked on the corner. It was still usable so i didn't bother to ask for another replacement. I would recommend item to be shipped in another box instead of an over-sized yellow envelop which is not adequate protection. Item sharpen my knife pretty good though..
Serrated blades have a grind on one side of the blade. Only sharpen the grind side of the blade. Hold the sharpener at the angle that matches the original edge angle. Hold the knife with the edge away from you and the serrated side of the edge facing up. Set the tapered diamond sharpener in a serration so that you fill the indentation. Draw the sharpener towards the edge.

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.

This 600/1,000 grit is my second Unimi knife sharpener, the first is 2,000/6,000 grit and I love them both. Both stones together produce very sharp and well polished knives that reduce the cutting effort and save time in the kitchen. I particularly appreciate that the manufacture printed the grit number on the side of each stone - that helps use the different grits in the proper sequence from the coarser to the finer. The stone comes with a non-slip silicone/rubber base which is very handy.
Absolutely solid item craftsmanship is top notch in general as to be expected from wazoo My only complaint is about my stone personally it's pretty bland and all white lacking in uniqueness and character there is one spot that shows some color when wet and it looks like it might be a weak point right on the top corner of the rounded end it may end up weakening with use and break off especially if it gets dropped but this is purely a fault and with the stone it's self and not with wazoo
The word “Novaculite” is derived from the Latin word “novacula”, which means “razor stone” and is essentially a metamorphic, recrystallized, variety of Chert composed mostly of microcrystalline quartz that is found in the found in the Ouachita Mountains of Arkansas and Oklahoma and in the Marathon Uplift of  Deposited in the Devonian Period and the early Mississippian Subperiod some 410 to 325 million years ago and subjected to uplift and folding during the Ouachita orogeny of the Atokan Epoch (early Pennsylvanian Subperiod), Novaculite is a very tough stone that is resistant to erosion and thus, the various layers of Novaculite stand out as ridges in the Ouachita Mountains. Thus, due to both its availability and its composition, it has been mined since ancient times for use as arrowheads and spear heads as well as in more modern times for use as sharpening stones.
I know that it is very helpful to watch a video of this process and the best videos of knife sharpening I have seen are out there for you. If you only watch one person sharpen a knife, watch Jon Broida from Japanese Knife Imports. Extremely professional videos and easy to understand. I have a couple of videos as well on my website but I really like what Jon has done for the sharpening community.

My first set of sharpening stones so I have nothing to compare them to. For $50, though, great price to get into the world of sharpening. Stones are great and easy to use. Was able to put hair shaving edges on knives. Took a couple of knives to feel comfortable and better with the process and how to sharpen, but the stones you get work great. Here's the secret though. Get the green leather stoping block as well. As great as the stone are, I have found that stroping the knife after the fact is what really brings out that razor edge. And after using the knife, stroping it again, will restore and keep it razor sharp. Hope you enjoy it as much as I am.