As a lay person I have to draw a line in the sand and trust the vendor's integrity and his product knowledge so he would be in a good place to detect a dud or fake. The Shobu Asagi Tamamoku I bought from Takeshi is my favourite stone of the four I have. Easily the best shaving edge I've been able to get from the naturals. It is a genuine competitor to high grit synthetic stones , given some mellowing on a pasted strop and you have the feel of this Shobu edge. That is high praise for any stone, and I admit to taking two razors to the bathroom when testshaving the Shobu edge, the spare was in case the Shobu edge wasn't up to it, and it was tops. I did a full three pass shave and it was easy going, I was amazed. So, if I wanted to outlay some big dollars and buy a Nakayama maruichi Maruka or similar, it seems a dangerous prospect, and really at my stage if progress on jnats, I probably wouldn't get the best out of such a stone although I'd like to try a fast cutter, that's not to say my Shobu is slow, it's steady. This is a real learn these jnats.