I have a friend who insists that the patterns that we see in so many Japanese knives and Swords are because ceramic is somehow put into the metal. He believes that the clay he sees in knife forging videos is somehow ceramic. I explained to him what Kurouchi was, why the clay (which he insists is ceramic) was used in quenching and tempering, and how the knives he is talking about are actually forged from multiple different types of steels giving it that look, utilizing different layers for specific cores, etc.
Is there a resource, or a video which explains this in detail so that I don't have to argue with him anymore? I've ran out of ways to tell him that clay = / = ceramic.
edit- he also insists that this "ceramic" is why Japanese knives/Swords NEVER (yes I said never) need sharpening. I showed him a few photos of a couple of my Japanese knives and he commented on how I never need to sharpen them, haha.
edit- OH, and he doesn't quite like the "rust" on my Konosuke (Mark's forced patina method).... I quite like it and I had no clue that Ceramic could rust