6 Important Facts About Rocks and Minerals

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If you are interested in rocks and minerals, you are not alone.  Many people are interested in the world of mineralogy, geology, and rockhounding, which involve the study and collection of rocks and minerals.  

There is plenty to learn about rocks and minerals.  So let me help you get started on these 6 important facts about rocks and minerals…

1. Rocks are not minerals.

Many will often use the words “rocks” and “minerals” interchangeably.  In fact, rocks are not minerals and minerals are not rocks.  Rocks and minerals are two different things, and that distinction is important.

I’m not one to get too critical on this topic, as I do understand the differences between the two.  If someone refers to a mineral as a rock, or rock as a mineral, I am not the type to get my undies in a knot over it!

Rocks are generally a hard mass that will contain minerals within it.  Minerals on the other hand, are concentrated chemical structures that are contained within the host rock.  They have many different characteristics that a rock may not have.

Minerals generally have a structured chemical composition as a crystalline form.  Even though at times that crystal structure may not be apparent as you look at it.

Example of a pair of clear quartz crystals. Quartz can often show as large visible crystals. On the other hand, quartz can come in many different forms where the crystal structure is not as visible as these displayed crystals.

For more information on properties of minerals, I have a great article on physical properties of minerals “9 Important Physical Properties of Minerals”.  This article is a good one on learning more about some of the important physical properties that minerals have.

If you are interested in learning more on the differences between rocks and minerals, I “highly” suggest looking at my article “What are the Differences Between Rocks and Minerals”.  This article will go into more informative detail on what a rock is, and what a mineral is.   

2. Three types of rocks, hundreds of minerals.

There are three types of rocks; Igneous, metamorphic, and sedimentary.  These three types of rocks are different in how they were created.  Many rocks of these three types can be quite unique that some may confuse them as minerals.

For some great examples, with pictures, of Igneous rocks, Metamorphic rocks, and Sedimentary rocks, see my articles; “Examples of Igneous Rocks”, “Metamorphic Rocks”, or “Examples of Sedimentary Rocks”.

There are hundreds of different types of minerals out there on our earth.  Often, most people interested in rocks and minerals are drawn more to the minerals than the three different types of rocks.  This is due to many minerals being very striking in appearance.

Here is a picture of some quartzite rocks. They don’t really look to spectacular, unless you see the inclusions of quartz reflecting in the sun. Compare this to the next picture…
Some loose Amethyst and Citrine. Which one would you be more interested in collecting, these minerals or the quartzite rock above?

Here is an article showing off some of the more common examples of minerals.  “Common Examples of Minerals”.  There are some great images on there showing some of the best examples of minerals.

Luster is one of the big distinguishing physical features of a mineral.  I wrote an article called “The Best Examples of Luster in Minerals” that has quite a few nice pictures in there as well if you want to take a look.

3. Rocks have a rock cycle.

Rocks have a unique cycle called the Rock Cycle.  This rock cycle is a roadmap on how rocks are formed, broken down or changed, then formed again.   The rock cycle is the overall and general means in which the earth is continuously changing with time.

Minerals are obviously part of that rock cycle as they are contained within the rocks themselves.  Minerals are not often mentioned when talking about the rock cycle, but keep in mind they are there.

For more understanding and a clearer view on the rock cycle, read my article “Diagram of the Rock Cycle”.  This article is often used in a google class every now and then, and can definitely bring some insight on this important earthly cycle.  

4. Minerals have a crystal structure, rocks do not.

One of the biggest distinguishing facts about minerals that set them apart from rocks, are minerals have a crystal structure.  Some minerals are quite obvious in their crystalline structure, such as quartz or topaz, while others like carnelian or malachite are not.

Sedimentary, metamorphic, and igneous rocks will never express any sort of a crystal structure.  You may see crystal type structures within the rock, like small pockets of air with crystals, but that does not make the rock have crystal structure. 

Here is a great example of host rock, Rhyolite, hosting some very light purple amethyst crystals. These crystals formed in the open pockets of air within the rock.

5. Rocks and minerals are needed in everyday uses.

The mining of rocks and minerals for use is probably one of the single most important things humanity has done, and continues to do.  Rocks and minerals have been key in our advancement of technology, tools, structures, medicine, and improving our life and our quality of life.

Your everyday life is filled with the use of rocks and minerals.  Minerals are constantly used in many of the products and items you have around your living space.  While rocks, in their more natural form, are used as the building materials that make up your living space.  Don’t forget rocks make up  the roads and other structures you enjoy around your community. 

6. Magma is melted rock and minerals

Magma, while underground, and lava, while above the surface, is liquid rock and minerals at extreme temperatures up to 2700 degrees Fahrenheit.  When magma cools it will cool as igneous rock.  This igneous rock contains minerals within.  

At times the minerals within the rock will become concentrated.  This happens by various natural occurrences such as heating, cooling, pressure, air pockets, and liquid flow within the rock.  This concentration of a mineral is in the form of crystallization.

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