*NOTE: As much fun and pretty as these crystals may be please be aware that this is metal. Melting metals will give off fumes; try to avoid breathing in those fumes for health reasons. For complete details on bismuth and its' properties please read the Material Safety Data Sheet (MSDS) found here: http://www.sciencelab.com/msds.php?msdsId=9927101
Metal Bismuth (99.999% pure bismuth is preferred. The cheapest place to acquire some is at Roto's Metals; they sell it by the pound: http://www.rotometals.com/Bismuth-s/4.htm)
2-3 Stainless Steel cups (stainless steel is preferred but aluminum cup will work too. They can be found at any store that sells kitchen accessories. For this example a muffin tin was cut up and used.)
Stove top or Hotplate (propane torch optional) (The hotplate can be found at almost any chemical store online.)
Step 1: Melting the Bismuth
Place the stainless steel/aluminum cups into the stove top/hotplate and turn it to medium-high
Wait and watch for the bismuth to begin melting. If not turn up the stove top/hotplate.
Optional: if the stove top/hotplate does not get hot enough to melt the bismuth, a propane torch can be used to carefully melt the bismuth. WARNINGpropane torches are very hot and dangerous. please wear proper hand protection and eye protection before use.
Wearing the oven mitt(s) shake the container and watch for ripples in the liquid bismuth to check and see that it has all melted.
Step 2: Pouring the Bismuth
Wearing the oven mitts (and tongs if possible), carefully pick up the container of liquid bismuth and quickly pour it into the other cup and set the hot cup aside. (try to pour the bismuth without pouring the gray layer on top; it contains impurities which could inhibit the crystals.)
Turn off the stove top/hotplate that the second cup with the freshly poured liquid bismuth is on. The rate of cooling down affects the size and the structure of the bismuth crystals so the slower it cools down the better.
Step 3: Bismuth Crystal
Quickly pour the liquid bismuth into the first container that was used. There should be bismuth crystals in the second container.
The bismuth crystals can be snapped out of the container after the bismuth is completely solid, or they whole shape can be saved. Crystals should form in the other container as well.
If the crystals are not to your liking, the bismuth can be remelted and the process can be repeated until the desired crystals are made.