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Off Topic / Re: Chemistry stuff topic
« on: September 17, 2008, 01:29:10 AM »
There's not much information on Bismuth, but I found this which gives the general idea.
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I may be able to offer some insights on how to grow bismuth crystals. We have been doing it for sometime in a rather low tech way on an old electrical kitchen stove we bought for that purpose. We just take the metal, it has to be quite pure and put it in a stainless steel bowl and heat it up to melting and then cool it off.
We have to insulate the bowl to keep it from cooling down too much and we also have to insulate the top which we do by floating an insulating substance on the top of the bismuth with little screws going down through the insulation into the molten bismuth and then let the melt cool down a little. At the proper time you just lift off the insulation and magically there are beautiful bismuth crystals growing on the screws.
It is a bit of an art form and takes some trial and error to get a feeling how long you have to wait. Wait too long and the bismuth crystals grow "wall to wall". We really have not managed to work out the kinks to make it more than marginally successful in a commercial sense. To do that you need to grow the bismuth crystals so that they are long and slender or very hoppered so that you get maximum visual appeal for the amount of bismuth in your crystal cluster...
Always consider safety first when working with molten metal at these temperatures. Use the purest bismuth you can obtain.
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The crystals form floating in a supercooled bismuth melt and actual growing time is about 5 - 10 minutes