Crystals of the mineral Pyrite from Peru
Click on image for full size
Courtesy of Corel

Type of Minerals

So far, over 2000 minerals have been found, and every year new ones are discovered. This is a pretty overwhelming number of different types of minerals, however, you don't need to know them all to be a rock hound. In fact, only a few dozen are common within the rocks of the Earth's crust so it is only a limited number of minerals that you are likely to find in your backyard.

Minerals are divided into different groups based on their chemical components.

Silicate minerals
The most common mineral group on Earth is the silicate minerals, which all have the elements silica and oxygen as their primary components. Most silicate minerals form when molten rock cools. Molten rock at or near the Earth's surface cools very quickly and crystals stay very small because they don't have time to grow large. Molten rock that is deep underground, where temperatures and pressures are very high, will cool slowly allowing time for large crystals to grow.

Non-silicate minerals
There are many different groups of other minerals that are known as non-silicate minerals. Some of these groups form when magma cools, while others form when water evaporates away, or when other minerals decompose.


Last modified March 4, 2003 by Lisa Gardiner.

You might also be interested in:

Traveling Nitrogen Classroom Activity Kit

Check out our online store - minerals, fossils, books, activities, jewelry, and household items!...more

It’s Not Your Fault – A Typical Fault, Geologically Speaking, That Is

Some geologic faults that appear strong and stable, slip and slide like weak faults. Now an international team of researchers has laboratory evidence showing why some faults that 'should not' slip are...more

What Is a Mineral?

Minerals occur naturally on rocky planets and form the building blocks of rocks. They are non-living, solid, and, like all matter, are made of atoms of elements. There are many different types of minerals...more

What’s That Mineral?

Each type of mineral is made of a unique group of elements that are arranged in a unique pattern. However, to identify minerals you don’t need to look at the elements with sophisticated chemical tests....more

Quartz

Quartz is the second most common mineral in Earth’s crust. It is a member of the quartz group, which includes less common minerals such as opal, crystobalite, and coesite. Silica (Si) and Oxygen (O) are...more

Mica Minerals

Mica minerals make some rocks sparkle! They are often found in igneous rocks such as granite and metamorphic rocks such as schist. They sparkle because light is reflected on their flat surfaces, which...more

Feldspar

Feldspar is the most common mineral in the Earth’s crust, so you are very likely to find it in the rocks you collect! It is found it all of the three rock types, but is most common in intrusive igneous...more

Olivine

Olivine looks like little green crystals. It is typically found in some igneous and metamorphic rocks. Often the crystals are so small that you need to use your hand lens or magnifying glass to see them...more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part is sponsored in part through grants from federal agencies (NASA and NOAA), and partnerships with affiliated organizations, including the American Geophysical Union, the Howard Hughes Medical Institute, the Earth System Information Partnership, the American Meteorological Society, the National Center for Science Education, and TERC. The American Geophysical Union and the American Geosciences Institute are Windows to the Universe Founding Partners. NESTA welcomes new Institutional Affiliates in support of our ongoing programs, as well as collaborations on new projects. Contact NESTA for more information. NASA ESIP NCSE HHMI AGU AGI AMS NOAA