It may also mean than Krans shouldn't wear anything, otherwise they could die from asphyxiation. 
Well, you can't drown a cockroach without completely immersing it... (seriously. Try it.)
But the nagging question I have is... why do they breathe? A silicon based life form, using oxygen, would likely produce silicon oxides - like silicon dioxide, etc. Someone earlier in the thread mentioned that they regenerate out to in, which kind of makes sense, but I'm not sure that this would work in the same way either.
Other questions would be about senses. Vision, etc. I mean - I appreciate the magic of Kran (my character is Kran), but if we start picking at it there's much that needs to be explained. The bit about 'munching diamonds' in one of the quests indicates carbon intake...
I do think that there is an easy way out of this, though. Through the history, the Kran were created by tapping the power of the Crystal. This involves magic, so a golem sort of concept works - but if someone wants to dig on the scientific side, I'd suggest that instead of strong acids digesting the nutrients... maybe it's more of nuclear fission. That explains how carbon could be used by a silicon based life form... :-)
