I read specs on an FR thread that said the tiles would protect to 2300F. Then I watch the Nasa press conference that said reenty was over 3000F. The 2300 stuck with me because that's the temperature at which porcelain "cures." You support porcelain in a kiln with this silica stuff that looks like quilt batting...the silica stuff looks exactly the same after firing as before you fire the kiln. It's called "prop"...I wonder if the tiles aren't made largely from this stuff.
Anyway, just a throwaway, an idle curiosity. Did you know that there are ceramic knives far harder and sharper than the best steel?
That sounds like the same or similar stuff that jewelers use as desk or bench pads when soldering and working with precious metals.
Yes, I heard of the ceramic knife not too long ago. Strange, but heck, the cavemen and native americans used certain rocks to make some pretty sharp cutting devices as well. Maybe, we are finally catching up technology-wise our ancient ancestors.