Re: ATM 2" hex ceramic tiles

["Nils Olof Carlin" <nilsolof.carlin@telia.com>]

Not that I have ground much glass, but I've used Portland cement without sand added - as 
long as the sand stays in place, all would be fine, but my imagination suggests some 
nasty things could happen during fine grinding when a few of those grains work loose from 
the rather soft matrix (I guess it is about as hard as limestone). It seems safer to mix 
it with pebbles, or even better with ceramic tiles ;-)
Nils Olof