Many materials naturally want to grow as crystals with atoms arranged in an organized, repeating fashion. This is because generally as a solid grow, it takes less energy to organize the atoms in this way than growing a solid with atoms in a random pattern.

Anyone can grow crystals through the evaporation and/or cooling of either a salt-water or a sugar-water solution. Amazingly, from the perspective of the crystal, there’s no difference between the growth of the salt or sugar crystals, the crystals highlighted in this TED-Ed lesson, or how the crystals grow in any rock. All crystals grow the same way. This webpage shows a number of movies of crystals growing and other supplemental information regarding crystals. Click here to learn more!

Not only are crystals a common way for solids to grow, but crystals have a number of important properties that we use in our everyday lives. For one, many crystals polarize light, which means that light interacts with such crystals in fascinating and beautiful ways. This is demonstrated by looking at a thin slice of a crystalline rock with a polarizing microscope, shown here. The change in colors as the rock is rotated is caused by how polarized light interacts with the crystals in the rock. This behavior is utilized in liquid crystal displays found in watches, calculators, and many flat panel televisions and computer monitors.

Computer chips and the light emitting diodes (LED) used in some flat-panel displays and lights all use crystalline semiconductors. Crystals are also used to generate lasers and are used in solar panels. Graphene, the next “supermaterial,” is also crystalline. Graphene is a single crystalline sheets of carbon atoms and is poised to revolutionize how electronics can be used and how society builds cars, bicycles, buildings, and space ships, just to name a few. Simply put, society relies heavily on the many unusual properties of crystals and major future technological advances will likely be driven by crystals.

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