What Are Minerals?

The mineral is a naturally occurring homogeneous solid with given chemical composition and a highly ordered atomic arrangement, which is generally formed by inorganic processes. There are thousands of mineral species known, but only about 100 of them form the main mineral components of rocks; these are known as rock-forming minerals.

Mineral elements make up the earth, either alone or in several combinations known as compounds. A single element or alloy makes up a mineral. A mineral is an inorganic element that occurs naturally and has a definite chemical composition and ordered atomic structure.

Examples of Minerals

1. Minerals are naturally occurring solid objects. They aren't even alive. A crystal is formed by fitting the atoms that make up a mineral together. While impurities or non-crystalline matter may be present, the chemical structure, or types of atoms in a given kind of crystal, is the same for all crystals of that kind. Minerals include gold, diamonds, rock salt, and the graphite used to render pencil "lead." 

2. Although each of these minerals is distinct, they often resemble one another or something else. An emerald-like piece of green plastic may be mistaken for an emerald. A rough diamond can appear to be a very smooth piece of quartz. 

3. Sodium chloride is the mineral that makes up table salt. Since it occurs in crystals formed like small cubes, it has an ordered structure. 

4. Quartz, also known as silicon dioxide, is another common mineral. The hexagonal form of its crystals is peculiar. Coal is a carbon-based mineral that was first captured by living organisms via the process of photosynthesis. 

5. As a consequence, some authorities object to the concept of a mineral as an inorganic material since the carbon in coal is of organic origin. 

6. Limestone is a type of rock made up of only one mineral: calcium carbonate. Igneous, sedimentary, and metamorphic rocks can be categorized into three groups based on their origin on Earth.

Classification of Minerals

1. Native Elements: The pure mineral belongs to this group. The majority of minerals are made up of chemical elements in different combinations. A single element, such as copper, is contained in a naturally pure form in this category.

2. Silicates:  This is the largest type of mineral. Metals are mixed with silicon and oxygen to form silicates. Silicates make up more of the earth's crust than all other minerals combined. This category contains the mica on the left.

3. Oxides:  Oxides are formed when a metal reacts with oxygen. This group includes everything from drab ores like bauxite to precious stones like rubies and sapphires. This group contains the magnetite seen to the left.

4. Sulfides: Sulfides are sulfur compounds that typically contain a metal. They are usually heavy and brittle. This group includes a variety of essential metal ores, including the iron ore pyrite, which is seen here.

5. Sulfates are sulfur-based compounds containing metals and oxygen. This barite belongs to a wide group of minerals that are soft and translucent.

6. Halogen: Chlorine, bromine, fluorine, and iodine are halogen elements that interact with metallic elements to form halides. They're very soft and dissolve rapidly in water. One well-known member of this group is Halite. Its chemical formula is NaCl, which stands for sodium chloride, or table salt.

7. Carbonates are minerals that contain carbon, oxygen, and a metallic element. Calcite, also known as calcium carbonate, is the most common carbonate mineral.

8. Phosphates are less common than the other mineral families in terms of occurrence. They are often formed as weathering breaks down other minerals. They are often vibrantly colored.

9. Mineraloids are substances that do not fit easily into one of these eight classifications. Mineraloids include opal, plane, amber, and mother of pearl.

How are Minerals Formed?

The four major types of mineral formation are: 

(1) Igneous, or magmatic, in which minerals crystallize from a melt,  

(2) Sedimentary, in which minerals form as a result of sedimentation, a process in which the raw materials are particles from other rocks that have been weathered or eroded, 

(3) Metamorphic, in which new minerals form at the expense of older ones due to the effects of changing—usually increasing—temperature, strain, or both on an established rock type, and 

(4) Hydrothermal, in which minerals form as a result of a process in which the raw materials are particles from other rocks that have been weathered

The first three processes create a variety of rocks with different mineral grains tightly intergrown in an interlocking cloth. Hydrothermal solutions, as well as very low-temperature solutions (e.g., groundwater), appear to follow fracture zones in rocks, which can provide open spaces for mineral chemical precipitation.

Did You Know?

Minerals containing uranium (U) and thorium (Th) undergo continuous decay reactions in which radioactive isotopes of uranium and thorium produce a variety of daughter elements as well as energy in the form of alpha and beta particles and gamma radiation. A Geiger counter or a scintillation counter can be used to measure the radiation produced in the lab or the field. Uraninite, pitchblende, thorianite, and autunite are all uranium and thorium-containing minerals that can be identified with a radiation counter. Several rock-forming minerals contain enough radioactive elements to allow the time since the radioactive material was incorporated into the rock to be determined.