Make Bismuth Crystals

A Rainbow labyrinth is formed from molten metall.

Scientific name: Molten bismuth metal forms crystals with oxide coat under gradual cooling.

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Bismuth crystals - amazing!

How to Make Bismuth Crystals

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Making Bismuth Crystals

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step by step grow bismuth crystals at home and gemstone work

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Make Bismuth Crystals

Safety

Wear eye protection goggles and gloves. Try to avoid breathing in melting metal fumes. Be careful working with liquid metal. Use pliers and tweezers to handle hot objects.

Always follow general safety recommendations. Please note that conducting chemistry experiments you must comply with the relevant legal procedures in your country.

Reaction formula

2Bi + 3H2O → Bi2O3 + 3H2

Reagents

  1. Bismuth

Step-by-step instruction

  1. Prepare two stainless steel measuring cups, a gas burner or a hot plate.
  2. Put a piece of bismuth metal into the first cup. Impurities will affect the crystal growth so try to get as pure metal as possible.
  3. Place the cup with bismuth on a hot plate.
  4. Heat it until the metal melts.
  5. Gray “skin” appears on the surface. It is formed by a large amount of bismuth oxide.
  6. Heat the clean empty cup.
  7. Slowly pour the liquid bismuth into the clean preheated cup. Try to avoid hitting the gray “skin”.
  8. Turn off the hot plate. Place the cup with bismuth on it.
  9. Crystals begin forming under cooling.
  10. Before bismuth fully solidifies pour the excess of molten metal to another cup.
  11. Crystals of very interesting shape are obtained. The crystal surface is iridescent.
  12. If you don’t like the crystal shape you can remelt it and try again.

Scientific background

Since bismuth has a relatively low melting point (271°C) it is possible to convert it into liquid state at home using a common gas burner or a hot plate. Under cooling it forms crystals of very peculiar shape resembling labyrinths with spirals and stairs. This is the result of different growth rate around the outside and inside edges. The two main factors that affect the process of crystal formation – the presence of impurities and the speed of melted metal cooling. The best crystals are obtained from pure metal under slow cooling. The color of Bismuth crystals also catches the eye. The oxide film is formed on the metal surface. The thickness of this film is different in different parts of the crystal and causes different wavelengths of light to interfere upon reflection. This feature allows bismuth crystals to vary their color from violet to blue, green, pink and yellow.

Danger:
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Published on 05 August 2015

  • Fire
  • Heating with fire
  • Explosion
  • Poisoned gas
  • Organic
  • Electricity
  • Solution
  • Oxidation reduction
  • Color change
  • Precipitate
  • Gassing
  • Catalyst