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Crystals

Crystals are all around you! They are pieces of matter where the molecules fit together in a pattern. This creates many different shapes and patterns. A few common types are amethyst, quartz, and even salt! When you think of them, do you think of jewelry? I know I do! Let’s learn about these beautiful rocks and how they are formed.

Amethyst held in hands.

Girl holding an amethyst cluster!

How do Crystals form?

There are many different ways that crystals form. But, they are all formed using the same basic concepts. A hot liquid (think magma!) cools, causing the molecules to harden. They form a repeated pattern, causing the crystal to grow. They can also form when water evaporates from a mixture, like salt crystals. There are many different types too!
Stones Arranged in order on Tree Bark

Where do Crystals grow?

Crystals grow all over the earth! They are more common in certain areas though, and there are even places where you can hunt for them. Some of the best areas to find them are deserts, volcanic ash beds, near limestone, or the Giant Crystal Cave in Mexico.
 
The Giant Crystal Cave is about 89 feet long and has some of the biggest crystals ever found! The main chamber is covered in selenite crystals or Gypsum, a very pretty white crystal.
A crystal cave.

Example of a crystal cave.

Types of Crystals

There are many, many different types of crystals. There is no difference in the way they are formed, but they can vary in shape, size, and color. The five most common types are:
 
  1. Calcite – Calcite is usually white, grey, yellow, or green. They are made out of limestone and marble and are one of the most useful crystals in the world. We use it in construction, water treatment, medicine, and even chalk!
  2. Celestine – Celestine gets its name from its beautiful blue color. It is widely used for fireworks, healing, and in metal.
  3. Citrine – Citrine is a very bright yellow crystal. It gets its name from the French word “Citron”, or Lemon. Citrine is a gemstone. Like most, we don’t use it for much besides its appearance. But, it is November’s birthstone!
  4. Corundum – Ruby and Sapphire are two types of Corundum. They are all the same thing, but they have different colors. They can be red, blue, green, or even purple! We use it today to make sandpaper and polish metal!
  5. Fluorite – Fluorite is a colorless, brittle crystal. The name comes from the Greek word fluere, meaning to flow. We use it in decorations and glass today. Did you know that Fluorite glows blue under a black light? Cool, right?
Quartz and rose quartz crystals on a dark table.

Example of Quartz and Rose Quartz.

Salt Crystals

Did you know that you can make your own crystals at home? All you need is hot water, salt, string, a refrigerator, and a few hours. The reason for this is because as the water evaporates, the molecules become very unstable and cling to the string. This encourages crystals to grow. 
 
Here is a video showing how to do this experiment.

Other Great Resources:

Written By: Hannah Bertoch.