[Rockhounds] How to make Fluorite octahedra?

[Alan Goldstein]

Since 1987, I've probably made more than 1,000 octahedra from 3" to 1/4" 
wide. I some time demonstrate chipping fluorite when I set up at the Clement 
Mineral Museum show. It is not something I would recommend as a kid's 
activity using the technique I was taught by miners 900 feet under ground in 
the Annabel Lee because it is easy to draw blood if your aim is off. I use a 
small sharp chisel that is about 12 cm long and 6mm wide. I hold a piece of 
fluorite in a way to get a clean blow on the 111 axis. If the fluorite 
octahedron is made from a well-formed crystal (obviously not a display 
quality piece), then it will be easy to make by chipping pieces of each 
corner. Unfortunately, unless you work in a fluorite mine, getting those 
great chipping pieces consistently can be a challenge. Intergrown crystals 
are a real bear to work with, as are some optical fluorites. I've chipped a 
couple of twinned crystals into two half octahedra (quadrahedron?), I also 
have octahedra with a chip of shale sticking out of one face and other 
minerals, too.

I've actually got a quantity of the gemmy yellow fluorite that is facet 
quality from the IL-KY fluorspar district. I don't know anyone who facets 
stones that would touch fluorite.

Alan


----- Original Message ----- 
From: "Johan" <mineral.maertens at att.net>
To: <rockhounds at lists.drizzle.com>; <rockhounds at lists.drizzle.com>
Cc: <rockhounds-request at lists.drizzle.com>
Sent: Tuesday, June 17, 2008 7:14 PM
Subject: [Rockhounds] How to make Fluorite octahedra?


> How can I teach children in our club to make fluorite octahedra?
> I assume: get the right kind of fluorite, use some kind of rock splitter, 
> right orientation etc.
> Have never tried it.
>
> --
>
> Johan Maertens
>
> -- 
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