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How to Grow Bismuth Crystals

Naturally-occurring bismuth is in the form of solid chunks or blocks. When heated, the blocks melt and form visually-appealing, spiraling, staircase-patterned, colorful crystals.
Priya Johnson May 4, 2019

Requirements

  • Stainless steel saucepan
  • Stovetop
  • Stainless steel spoon
  • Small, deep stainless steel bowls
  • Solid bismuth chunks
  • Leather gloves and safety glasses

Why Stainless Steel?

Stainless steel vessels are mandatory, because they have a higher melting point than bismuth. Other materials will melt under such temperatures. You can use aluminium vessels as well.

The saucepans and other utensils used to make these crystals must never be used for cooking again.

Quality of Bismuth Solid Matters

Bismuth metal found in nature is not in the crystallized form. When melted and cooled at a certain temperature, rainbow-colored, staircase-like crystals are formed.

The quality of the crystals formed will depend on the purity of the bismuth piece used. Bismuth metal is available in stores as bismuth ingots or chunks.

How to Make Bismuth Crystals

Step 1: Melt the Metal

The first step is to convert the solid bismuth metal into its molten state. This is done by heating the metal in the steel saucepan, until the whole metal block turns into a viscous, silvery liquid state.

Step 2: Discard Impurities

Impurities from the bismuth rise and form a sheet or skin on the surface. Use a spoon to scrape out the impurity layer. Once again leave the molten metal undisturbed till a skin is formed again.

Impurities hamper the crystallization process. To get good crystals, discard impurities as soon as they rise to the surface.

Step 3: Preheat the Bowl

While the molten metal is left to cool, place the steel bowl on the stove top and preheat it. The slightly cooled melted metal needs to be poured into this bowl.

Use the spoon to make a tear in the skin at the bottom, and pour the silvery liquid into this preheated bowl.

Step 4: Pour Out the Liquid

When the skin is formed on the surface of the molten metal; below the surface, bismuth crystals have started forming.

If you don’t pour out the remaining liquid, the rest of the bismuth liquid will solidify around the beautiful crystals, and you will be left with a solid piece of bismuth metal.

Step 5: Slow Cooling

The rate at which the molten state of the metal cools, has direct impact on the size of the crystals formed.

Large bismuth crystals are formed when the cooling is quicker, but slow cooling is ideal because it results in more intricately-designed crystals. Take out the crystals once they are formed with the spoon.
Shade of the bismuth crystal structure is determined by the temperature at which the molten bismuth molecules came in contact with air.

Bismuth crystals like candle wax can be melted to its molten state and solidified or in this case crystallized.