At the risk of letting your eighth-grade science teacher down, you have to admit that you don’t know, or at least remember, very much about how things like rocks and crystals are formed. In fact, you probably can’t say that you know the difference between a rock, or a crystal, or a gemstone. You also definitely can’t answer, “How do crystals form?”
Because of the way that these terms can sometimes be used interchangeably in colloquial speak, it’s actually pretty easy to get confused. This confusion is amplified by the fact that technically speaking, they are all the same. Rocks are formed from minerals just as the crystals that are cut and polished into gemstones are.
Okay, so a crystal is formed from minerals just like a rock is formed, but what makes crystals so special? It has to do with the specific way that crystals are formed. Just because they share the same basic component as a rock, does not mean that they turn out the same way.
How Do Crystals Form?
So to understand what makes a crystal special, you have to know exactly how one is formed. Here is a quick guide to help you answer, “How do crystals form?”
A crystal is a solid material whose components, like its atoms or molecules, are arranged in a highly organized way that can be observed on a microscopic level, or with the naked eye.
This orderly geometric structure provides a framework for the crystal to grow by giving it a pattern that new atoms can repeat over and over again. This process of repetition is called crystallization, and it is how crystals are formed.
The Process of Crystallization
An easy way to think of crystallization is as a way of bringing order to chaos.
Think of how you use the terms crystal and crystallization when it comes to a thought process. When your thoughts crystalize, or when things become crystal clear, it means that something that was once confusing now makes sense.
There is an order or pattern to your thinking the same way that there is an order to the atoms.
When water evaporates, or hot liquids like molten rock cool, crystals form to make sense of the rapidly changing elements. They find a way to remain stable in unstable conditions.
That is why scientists often refer to crystals as growing. Crystals grow as atoms come together, and the precise way these atoms come together determines the shape of the crystal.
The surrounding conditions also determine the shape of the crystal. Some crystals can be formed in a matter of days, and others take thousands of years to grow. Crystals can form in water, in carbon, or in magma.
Igneous rock is formed when magma cools and depending on the speed at which the magma cools, crystals can form. They form to help stabilize the molecules. Rock that cooled very quickly will have little to no crystallization, but rock that cooled slowly, like granite, is completely crystallized.
The Two Stages of Crystallization
Crystallization happens in two stages. The first stage is called nucleation when the atoms begin to come together in a pattern. This is typically either caused by a super-cooled liquid, like water freezing or magma cooling, or by a super-saturated solvent, like when salt crystals form as water evaporates.
The second stage of crystallization is growth. Under the right conditions, a crystal can continue to grow as long as it is given time. Of course, as the crystal grows, as it builds more and more atoms, it has more chances for mistakes or impurities to occur.
An impurity occurs when the pattern of atoms is interrupted. This can happen because of changes in temperate or the addition of a different type of atom. When the pattern is interrupted, perfection is lost. In a diamond, for example, this might cause the color to change.
In fact, impurities play such a role in crystallization that the only difference between a ruby and a sapphire is the type of impurities which then change the properties of the crystal altogether.
Crystallization occurs in nature all the time, but it can also be produced in laboratories under artificial conditions. Sometimes this is done to meet consumer demands as with precious and semiprecious gemstones, and sometimes it is done to mass-produce chemicals.
You’ll Notice Crystals Everywhere
The study of crystals is called crystallography, and it helps to answer, “how do crystals form?” You might not be quite at that level yet, but you have a working knowledge of the complex work of atoms used to create crystals.
In fact, you may find yourself noticing and contemplating the formation of crystals in the world all around you, and you’ll know that it’s just nature’s way of creating order out of chaos.