Close to? Hmm...
Use pistons to push DMND to the edge and let it die.
you dont realise that we dont give a single (?)
!set type dmnd none
You could use Lua...
(Just a side note: In real life, diamonds are very flammable - remember, they're pure carbon!)
get piston to push it out of the screen
There is a way, but it is VERY difficult, occasionally fusion puts bits of plasma on top of other elements, if you can get it to put 5 bits of plasma on the same bit of diamond for a short time it will turn it into bhol, destroying the diamond.