We got some nice fluorite crystals, along with some which were rather small, and some that were not as nicely colored.

Since the melting point of fluorite is apparently around 1400 C and our butane torch supposedly gets up to 1430 C we decided to see if we could melt them, with the vague and not too serious thought that this might give us a way to combine several smaller crystals into one larger crystal. We also thought this might be a way to incorporate some coper salts into the crystals to make them more colorful.

Set up

Wearing goggles (of course) we put a single smaller fluorite octet in a crucible with a small amount of copper sulfate. We took it outdoors (in case there was any out-gassing, especially from the copper sulfate), placed it on a concrete slab away from anything flammable, and hit it with the torch.

At first, nothing much seemed to happen.

Then the copper sulfate crystals began to turn white.

Then the fluorite began turning whiter, and something started making hissing / crackling sounds.

Then the crystal jumped (like popcorn) and we realized that it was breaking up.

The jumping was caused by parts breaking off, some with enough force to hop out of the crucible (from water trapped inside?).

Since having red hot shards of fluorite crystal flying around didn't sound like a good idea we stopped there.

Afterwards, when we looked in the crucible, we saw little flecks of metal that looked like (and probably was) copper from the copper sulfate.