Okay, change of plans!
Instead of dying an already exsisting Z-crystal, I've decided to create my own from epoxy cast.
I made a silicone mold of both side of the parts, so clamped together they should make the shape I want. I tried casting some Easycast this morning and just checked this afternoon. Unfortunately most of the casting I put in the mold had disappeared. Not sure exactly how it happened, but a few guesses I have are.
A. The casting soaked through the mold
B. I might have suffocated the casting with both sides of the mold
C. The casting somehow evaporated
I'm not really sure what to do currently. I need some advice from someone who knows what they're doing...