Minerals 101

What is a Mineral?

Minerals are the building blocks of all rocks. Presently there are about 4,000 minerals that have been identified. But what is a mineral besides a building block? A mineral is defined as a naturally occurring inorganic solid that has a definite chemical structure. The important part of that definition is the last part that states a mineral has a definite chemical structure. This definite chemical structure is what provides a mineral with its physical properties which in turn allows us to identify them.

If minerals make up rocks, what makes up minerals?

Minerals are made up of complex structures of elements. There are eight elements that make up most of these minerals; Oxygen, Silicon, aluminum, iron, calcium, sodium, potassium, and magnesium; they account for about 98% of the earths crust. From this point we have determined that elements are the building blocks of minerals and minerals are the building blocks of rocks.

What are the physical properties of minerals?

The common physical properties used to identify minerals include crystal form, luster, color, streak, hardness, cleavage, fracture, and specific gravity. However there are other properties used to identify minerals as well. These include reaction to acid, taste, smell, and magnetism. Some of these tests are more accurate then others when identifying minerals. For example color is not as reliable test as hardness. Since minerals such as quartz come in a variety of colors it’s hard to use color to identify them. However, when using the hardness/scratch test quartz has a definite number making it very easy to identify it. To see further definitions of any of the terms listed simply click on the word to be redirected to a glossary.

What are the steps to follow in identifying minerals?

Step 1: Determine what group of minerals; silicates or non-silicates; your mineral belongs to.

What's the difference between minerals being silicates or non-silicates?

Since there are so many minerals on the earth they have been divided and sub divided to make them easier to identify. The first division is determining whether your mineral is of the Silicate group or the Non-Silicate group.

Silicate minerals have silicone and oxygen in their composition. More specifically a silica tetrahedron makes up their internal structure. There are four types of structures that center on a silica tetrahedron in silicate minerals. They are single chain, double chained, sheet, and 3-D framework. Further more silicate minerals can be broken down into Light silicates and Dark silicates.

Every other mineral that does not have a silica tetrahedron in its structure is placed as a Non-Silicate. There are six sub groups of non-silicates they are; Carbonates, Oxides, Sulfides, Sulfates, Halides, and Native metals.

Step 2: Using your knowledge of the physical properties of minerals determine which properties the mineral has.

Step 3: Using the properties go to the mineral identification chart and follow it to figure out which mineral you have.

Minerals Flow Charts

Metallic Minerals

Non-Metallic Light Hard Minerals

Non-Metallic Dark Hard Minerals

Non-Metallic Dark Soft Minerals

Non-Metallic Light Soft Minerals