[Rockhounds] Re: How to make Fluorite octahedra?

[Axel Emmermann]

> sufficient courage to run out naked and shovel all the snow 
> of our driveway and of all our neighbors (I am making this 
> up, we were actually wearing thongs).

I wonder if it would be considered "sound logic" to propose this: since
there were never any longitudinally sliced coprolites found, it is highly
probable that dinosaurs never wore thongs.

> Back on topic:
> Required are fluorite and pocket knives en children to make octahedra.
> Somehow these three together do not make me comfortable.

Seriously (for just a sec):
Calcite would be easier in view of the "flatness" of the cleavages. (I hope
this message makes it through the spam-filters... Cleavages and thongs in
one message may be a bit risky ;-))).
With fluorite the cleaving doesn't takes place in the same plane as the
supporting crystal face.
 
> I will have them practice first on sugar cubes with plastic 
> table knives.
> Note: Axel, there are no Tierlemont-cubes in the USA, mail me 
> some "klontjes" will ya..

Definitely a no-no! Kids are already hooked on sugar far to much as it is!
Have some consideration for their health.
Maybe you can have them practice their cleaving skills on large nitrogen
triiodide crystals... Lead picrate has also some funny side-effects (like
coloring the flying body parts yellow) but picric acid is just as much fun.
Or maybe even Mercury(II)fulminate. Or silver fulminate... That will even
detonate under water!

Cheers
Axel