There were quite a few questions about them, after the last post. So I'll share what I know.
EXACTLY how they're made is a mystery, because it's proprietary information. The one documentary I managed to watch on the subject of industrial ceramics, when they got to the cutting implements, they toured a factory and weren't allowed in half the rooms. However, from cruising the site over at Kyocera (I notice they're also selling ceramic-based ballpoint pens... hmmm), I see they say absolutely NOTHING about how the ceramics are made. But from the properties they have, I assume they're really either ceramic/glass or ceramic/metal composite. It looks and acts more like ceramic/glass should behave (breakage), but when it comes to composite I wouldn't count entirely on that to tell you what it is. But I'm guessing some kind of high-temp ceramic/glass composite.
Anyway, the material is really hard. Harder than metal. Which is, as with most things, both a benefit and a liability. Because it's SO incredibly hard, it's incredibly brittle, and doesn't flex at all. However, the lack of flexibility makes it possible for the ceramic to hold a sharper edge than metal. These are so hard and weird that you have to send the knives back to the factory for sharpening.
See, when you sharpen a metal knife, you get to a stage where the edge is so thin it can't support itself and either folds over or rolls up on itself. So metal knives are kind of intentionally dull; after sharpening, they knock off that folded over edge (the burr). While I'm sure ceramic (and any other material) will do the same thing, the 'point of collapse' where the edge is too thin and breaks off, is far thinner than with metal. (Am I making sense? I'm more an organic, non-metallic chemistry kind of girl.) Long story short, on a molecular level, ceramic is harder and so can hold a thinner - and therefore sharper - edge.
What's this all mean in real life? They feel funny when you use them. You may not think so, but after a lifetime of using metal knives, we're all used to our knives flexing. Cheapass knives flex a LOT, but even good knives have a little bit of flex in them. It's just how metal WORKS. So you use a ceramic knife, and you notice almost immediately that it isn't flexing a damn bit. I don't know about other people, but for me it makes me handle them a bit more cautiously. The only thing I used to use my ceramic knife for (I've had one for about ten years; just not a whole block of them) was slicing. Cutting thin slices of meat, cutting thin-skinned fruits like tomatos, that kinda thing. Dicing and mincing and like that is good, too, though I find for mincing I like the rocker-shaped blade of my metal chef's knife better. Anything that leads to a knife wedged into a big chunk of food (pot roasts, watermelons, bodies) is asking for breakage. I'm told chefs use these a lot for mincing up herbs, where you need lots of 'sharp' and not any 'crush'.
They're also super-sharp, to a disturbing level. I once cut entirely through a chicken leg (including the bone) by ACCIDENT, without realizing it. I'm only half kidding about how I'll eventually lop off a finger with one of these. More than capable of handling a banana or ten.
I confess, we also have a ceramic vegetable peeler. (The Perfect Peeler at the top of the page.) The husbeast does the bulk of the potato peeling at our house, and I bought it for him last Christmas as a gag gift more than anything else, but he loved it. I've used it since then, and it is AWESOME. Smooth as a baby's butt, and the peels come right off. And it's reasonably priced and everything.
So, food for thought. Basically, like everything else, ceramic knives are great, except for when they're not. I won't be giving up my (metal) boning knife any time soon.
Damn it. Now I want the pink santoku. And if I breathe a word to the husbeast, the crazy fucker will go buy it when we've got knives coming out our ears. (Just for the record, price-wise, these are about equal to high-quality home kitchen metal knives like Henkel's. But I still don't need a pink ceramic knife.)
Ooo! Look! Henkel's has a section on knife skills!