Grow Metal Crystals

Metal Crystal Growing Projects

Stibnite crystals

 Adrienne Bresnahan / Getty Images

Metal crystals are beautiful and easy to grow. You can use them as decorations, plus some are suitable for use in jewelry. Grow metal crystals yourself from these step-by-step instructions.

Key Takeaways: Grow Metal Crystals

  • Like other elements, metals form crystals.
  • Metal crystals are different from crystals grown from water-soluble compounds.
  • The easiest way to grow a metal crystal is to melt the metal and let it crystallize as it cools. For crystals to form, the metal needs to be fairly pure.
  • Another way to grow metal crystals is to react solutions that contain metal ions. This works when the metal crystal you want to grow precipitates from the solution.

Silver Crystals

This is a photo of a crystal of pure silver metal, deposited electrolytically.
This is a photo of a crystal of pure silver metal, deposited electrolytically. Note the dendrites of the crystals. Alchemist-hp, Creative Commons License

Silver crystals are grown from a chemical solution. The most common solution for this project is silver nitrate in water. You can watch the crystals grow under a microscope or you can allow the crystals to grow for a longer time to use them in projects or for display. Silver crystals are an example of "fine silver," which is silver of high purity. Over time, the silver crystal will oxidize or develop tarnish. This tarnish is black, unlike the greenish patina that forms on sterling silver from the presence of copper in the alloy.

Bismuth Crystals

Bismuth is a crystalline white metal, with a pink tinge.
Bismuth is a crystalline white metal, with a pink tinge. The iridescent color of this bismuth crystal is the result of a thin oxide layer on its surface. Dschwen, wikipedia.org

Bismuth crystals may be the prettiest crystals you can grow! The metal crystals form when bismuth is melted and allowed to cool. Initially, bismuth crystals are silver. The rainbow effect results from natural oxidation on the surface of the crystals. This oxidation process occurs very rapidly in warm, moist air. Bismuth is fairly soft, but some people make pendants using bismuth crystals or even earrings or rings.

Tin Crystal Hedgehog

These are real hedgehogs, though you can grow metal ones using chemistry.
These are real hedgehogs, though you can grow metal ones using chemistry. Thomas Kitchin & Victoria Hurst / Getty Images

You can grow tin crystals using a simple displacement reaction. This is a quick and easy crystal growing project, producing crystals in one hour (viewed live using magnification) to overnight (larger crystals). You can even grow a structure that resembles a metal hedgehog.

Gallium Crystals

This is a picture of pure gallium metal crystallizing from melted liquid gallium.
This is a picture of pure gallium metal crystallizing from melted liquid gallium. Tmv23 & dblay, Creative Commons License

Gallium is a metal you can melt safely in the palm of your hand. Of course, if you're worried about contact with the element, you can also melt it in a gloved hand. The metal forms different crystal shapes depending on the rate of cooling. The hopper form is a common shape, which is similar to that formed by bismuth.

Copper Crystals

Copper crystals (natural mineral)

 ScottOrr / Getty Images

Copper sometimes occurs as a native element. While you could wait a geological age for natural copper crystals to grow, it's also possible to grow them yourself. This metal crystal grows by electroplating it from a chemical solution. This method can also be used for nickel and silver. To grow copper crystals, you either need copper acetate or else you can prepare it. Make a copper acetate electrolyte solution by mixing a solution that is half distilled vinegar and half regular household hydrogen peroxide (not the super-concentrated stuff sold a beauty supply stores). Next, drop a copper scouring pad in the mixture and heat it until the solution turns blue.

You need a source of copper to feed the process. You could use a bundle of fine copper wire, but a copper scouring pad also works well because it has a lot of surface area for crystal growth.

Now you're ready to electroplate the copper ions from the solution onto a substrate (your substitute for the rock used in nature). The substrate (usually a metal, such as a coin) needs to be cleaned before use. You can apply a metal cleaner or a degreaser. Then, rinse well.

Next, attach the scouring pad or copper wire to the positive terminal of a 6-volt battery. Connect the substrate to the negative side of the battery. Place the scouring pad and substrate in the copper acetate electrolyte solution (not touching). Over time, the battery will electroplate the substrate. It's a good idea to add a stirring bar to agitate the solution to evenly distribute the ions and the heat. Initially, you'll just get a film of copper over the object. If you let the process continue, you'll get copper crystals!

Gold Crystals

Gold crystals

 plastic_buddha / Getty Images

Pretty much any alkaline earth or transition metal can be grown using the techniques described here. Although it's highly expensive and impractical, it's even possible to grow crystals of gold.