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I crystallised my bismuth!

 

it's so rediculously easy to do. I don't know why people dont have bismuth crystallising parties every week. It's awesome fun to do.

 

The only slight difficulty is that it's very hard to take a photo which does justice to the colours.

 

I'm very proud of my bismuth crystals. I plan to make more.

 

Here's the few photos which did work out:

 

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this experiment is cheap, fairly safe and awesomely rewarding.

 

Interestingly, my original sample of bismuth (which had been entirely cooled in its container and not crystallised in the fashion above) appeared to be paramagnetic. The new crystals are diamagnetic.

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You'd need a bunsen, two small metal pans (i used measuring cups), a pair of heat-proof gloves for safety, and a pound or so of bismuth.

 

The bunsen and the pans i'll have to leave up to you. The gloves you could probably get away with using oven-mitts, although you'd be better off with purpose built safety gloves. The bismuth can be purchased online, but I'm not sure if you have to be registered as some kind of institution to be able to get it. I don't think so because I originally found it on amazon.com.

 

Once you have all the apparatus, set up one pan (clean... everything must be very clean or it won't work) above a bunsen burner. Use a tripod or a clamp and retort stand. Get a heat-proof surface ready and put your other pan (clean and also empty) on the surface. Light your bunsen and set it on a blue flame so it's as hot as possible. It will take about 5 or ten minutes to melt the bismuth. Once it's melted, turn off the bunsen and wait about 3 to 5 minutes. The bismuth will form a dirty grey skin on the surface. Pick up the pan containing the molten bismuth VERY carefully with your heat-proof glove and pour it immediately into the empty pan. Allow everything to completely cool and then give the original pan a sharp tap, face-down on a surface. The crystals will fall out.

 

Alternatively you can buy these crystals fairly cheaply online.

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Hi.

Am missing too many things with the growth of these crystals; can someone clarify details please ?

 

As the molten bismuth is slowly cooling, do the crystals form embedded in the liquid, under the surface, as 'a diamond in a glass of water' :rolleyes:; Is that right ?

 

Pouring out the molten metal leaves the solidified crystals in the pot, attached to portions of solidified metal ?

How come the 'being poured out' molten metal does not leave particles and 'dew' attached to the crystals crevices ? They look soooo shiny and clean and smooth !

 

Do crystals grow only while submerged in their slightly hotter surrounding metal ? After the molten metal is drained, the crystals do not continue to grow, do they ?

 

Does it make sense to say the longer the time waiting to pour out the molten metal, the larger the crystals would be ?

 

But it is mandatory to drain before all becomes a solid piece, right ? ... Like 'the diamond being now captive in ice' :rolleyes:

 

If the melting pot had a cover, (with little air gap) there would be less/no formation of the grey layer on the surface because of less oxygen to produce it, is that right ?

 

Is cooling preferred to start in the bottom of the core (if it was possible), and keep the pot walls hotter to achieve a better ideal draining?

 

Edited: a nice site ----> http://www.amazingrust.com/Experiments/how_to/Bismuth_Crystals.html

 

Thanks. :confused:

Edited by Externet
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Hi.

Am missing too many things with the growth of these crystals; can someone clarify details please ?

 

As the molten bismuth is slowly cooling, do the crystals form embedded in the liquid, under the surface, as 'a diamond in a glass of water' :rolleyes:; Is that right ?

 

Pouring out the molten metal leaves the solidified crystals in the pot, attached to portions of solidified metal ?

How come the 'being poured out' molten metal does not leave particles and 'dew' attached to the crystals crevices ? They look soooo shiny and clean and smooth !

 

Do crystals grow only while submerged in their slightly hotter surrounding metal ? After the molten metal is drained, the crystals do not continue to grow, do they ?

 

Does it make sense to say the longer the time waiting to pour out the molten metal, the larger the crystals would be ?

 

But it is mandatory to drain before all becomes a solid piece, right ? ... Like 'the diamond being now captive in ice' :rolleyes:

 

If the melting pot had a cover, (with little air gap) there would be less/no formation of the grey layer on the surface because of less oxygen to produce it, is that right ?

 

Is cooling preferred to start in the bottom of the core (if it was possible), and keep the pot walls hotter to achieve a better ideal draining?

 

Edited: a nice site ----> http://www.amazingrust.com/Experiments/how_to/Bismuth_Crystals.html

 

Thanks. :confused:

 

I wouldn't say the crystals were "embedded" in the liquid, it's just the same as ice in water, except a lot hotter and metallic. Bismuth is unusual in that the crystals are lighter than the liquid... some of them form at the bottom (attached to the pan) and some form floating on the surface.

 

The crystals do not and can not continue to grow after the liquid is poured off. There would be nothing for them to form from. It's just like ice in water. Pour off the water and the ice cannot grow.

 

it doesn't make sense to say that the crystals get bigger over time. As the solid becomes a solid mass in the pan, it changes its structure from the rhombohedral structures you see in my photos to a flakier more "normal" looking metallic structure. There is a perfect time to pour off the liquid to get the best crystals and it's when about one third of the metal has solidified.

 

Yes it's important to drain it before it becomes a single piece. A single piece has no beautiful crystals and has a different structure. it's also paramagnetic and i wanted diamagnetic crystals for a demonstration.

 

A cover for the melting pot might help but i havent tried it.

 

The process works perfectly if you just let it cool naturally. It tends to crystallise from the bottom upwards but sometimes crystal form at the surface too.

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I don't know how you got bismuth that was paramagnetic. The stuff that I have was cast from an old tin can in the dent in the bottom of a soft drink can (ie about as primitive a setup as you can get). It wasn't particulary pure- not least because it probably dissolved the tin from the can.

It still serves its purpose- A small magnet is suspended between two lumps of it by diamagnetic repulsion (and a big magnet above the system).

Bismuth is diamagnetic as a solid. Unless you are at some bizzare pressure so it forms a different crystal structure, it will always be diamagnetic.

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I don't know how you got bismuth that was paramagnetic. The stuff that I have was cast from an old tin can in the dent in the bottom of a soft drink can (ie about as primitive a setup as you can get). It wasn't particulary pure- not least because it probably dissolved the tin from the can.

It still serves its purpose- A small magnet is suspended between two lumps of it by diamagnetic repulsion (and a big magnet above the system).

Bismuth is diamagnetic as a solid. Unless you are at some bizzare pressure so it forms a different crystal structure, it will always be diamagnetic.

 

Look at its electronic configuration. It SHOULD be paramagnetic. I havent a clue why, but when it's normally cooled (wihtout any fancy crystallisation) it's paramagnetic. Ive taken a peice which is paramagnetic, crystallised it, observed diamagnetism and then melted it again only to see the paramagnetism come back.

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