Diamond is the hardest material and therefore, anything else can be cut or drilled with it. If you are cutting or drilling through very hard materials such as Sapphire then bear in mind you will need a lot of patience and perhaps more drill bits than you would if you were drilling a hole through glass or Opal.
Will A Diamond Hole (Core) Saw Cut Through Wood?
This Video Shows The Result!
Question: When cutting through marble with a wooden underlayment do you need both a diamond hole saw and wood hole saw?