Maybe it's worth approaching Naniwa Abrasives and see if it's some sort of batch issue. There are too many users with these cracking or crazing problems. As I mentioned earlier I've used Chosera and superstones for more than five years, soaking them, doing nothing remotely as far as treating them in any careful way. I've followed gssixgun's video the whole time I've been using straights and I won't be changing anything. As far as climate goes, coldest mornings in winter wouldn't get below 4Celsius, and hottest day in summer of 42-43 Celsius. We do have high humidity most of the time. I'm close to Onimaru55, as far as climate is concerned, like an hour and a half drive. I'm on my second set of superstones and never had a drama.