What is the Difference Between a Rock and a Mineral?
Rocks vs. Minerals
Rocks vs. minerals. Let’s look at a side-by-side comparison of rocks versus minerals so you can see the difference between the two. Rocks are aggregates of one or more minerals. They also contain mineraloids and organic remains.
Now, mineraloids are minerals lacking crystalline structure. They don’t have a definite crystalline structure if they are mineraloids. Organic remains are going to be anything that came from a living thing. If an animal died, then its body would eventually decay and be organic matter.
Any kind of excrement from an animal would be organic remains. All of that also can form up rock. A rock is an aggregate or a combination of one or more minerals. It could contain mineraloids and it could contain organic remains. There’s no real set combination of what a rock is going to contain.
It has no definite structure or shape. A rock doesn’t have to have a certain structure. It doesn’t have to look a certain shape, look like a certain shape whenever you find it. Rocks are more random. We are not going to find them looking the same way every time. Now, minerals are naturally-occurring inorganic solids.
Nothing organic about them. Nothing that came from a living creature or a person. They have a definite chemical composition. If you were to look at it, every atom of that mineral should have the same chemical composition and an orderly internal crystalline structure.
Some minerals may have the same chemical composition but have a different crystalline structure. The structure determines how it’s going to look or what the mineral is going to be called sometimes whenever it has the same chemical composition. That’s a mineral.
A mineral at its basic point is a naturally-occurring inorganic solid, made naturally from the earth, and is doesn’t have anything that used to be alive. It has a definite chemical composition and a definite internal crystalline structure.
It’s got to form the same way every time to be a specific mineral. A polymorph is two minerals with the same chemical composition but a different crystalline structure.
This is what I was talking about where sometimes, even though two minerals will have the same chemical composition, they will look the same, because their crystalline structure is different. At that basic atomic level, the crystalline structure is different.
What you’re able to see with the naked eye is going to appear different. Even if it looks like two different minerals, it isn’t going to be the exact same. It will be a polymorph of the other, because it doesn’t have the same crystalline structure, even though it has the same chemical composition.
Rocks are more random. They don’t have to have a definite structure. They don’t have to have a definite chemical composition or makeup. They can be made of any combination of minerals, mineraloids, and organic matter.
Minerals are going to have a definite chemical composition and an orderly internal crystal structure. They are more specific. They have to have a definite composition and structure to them, where rocks do not have to have that.
Rock types are igneous, sedimentary, and metamorphic. These are the three rock types that a rock can be classified as. Rocks are classified into one of these three types based on their formation and the minerals they contain.
How are they formed and what are they formed of? When you know those two things, you can classify your rock as igneous, sedimentary, or metamorphic. Minerals are classified by their chemical composition.
You look and see what chemicals it’s made up of, what exact atoms make up that mineral at a chemical level, at the tiniest level, and that’s how they’re going to be classified. Rocks are classified by how they’re formed.
Are they formed from stress? Are they formed from heat? Are they formed from organic matter? Those kinds of things are going to affect how a rock is classified, but that doesn’t matter for a mineral. Lastly, the study of rocks is known as petrology, and the study of minerals is known as mineralogy.
Side note: geology is this study of Earth as it pertains to the composition, structure, and origin of its rocks. Rocks are classified based on their formations and what minerals are in the rock. Minerals are classified by their chemical composition. At that basic root level, what are they made up of?
Petrology is the study of rocks. Mineralogy is the study of minerals. Rocks are more random. They don’t have a definite structure. They’re made up of one or many different minerals plus mineraloids and organic matter. Minerals are more specific. They have to have a definite chemical composition and definite crystalline structure.