Minerals

Minerals are defined as solid, inorganic, naturally occurring substances with a definite chemical formula and general structure. Almost all chemical Elements in the Earth’s crust are associated with at least one mineral. They vary in color, hardness, density, crystal form, crystal size, transparency, composition, location, and abundance. Some minerals are radioactive (uranophane), while others are magnetic (magnetite). Some are uncombined elements, such as gold, silver, sulfur, bismuth, copper and platinum. Certain minerals, such as fluorite (calcium fluoride), glow with a vibrant luminescence after exposure to ultraviolet Light. Feldspar (a potassium aluminum silicate) and quartz (silicon dioxide) are the most abundant minerals found in the Earth’s crust. Mankind has coveted many minerals and gemstones due to their striking, beautiful colors. Some specimens of opal exhibit iridescent, rainbow-like colors within their crystals, while some specimens of the gemstone tourmaline show progressions of watermelon-like green to pink color from one side of a crystal to another. Although interesting, a few minerals are deceiving; many amateur prospectors have been tricked into thinking they have found gold, but have instead found pyrite (iron disulfide), otherwise known as “Fool’s Gold” due to its uncanny resemblance to the precious Metal. Diamond, the hardest natural substance found on Earth, has long been prized as the most desirable of all minerals due to its stunning interaction with light. Most diamonds, though, are impure and not suitable as gemstones; instead, they find industrial use as cutting tools, and are even made synthetically to meet this demand.

What Makes a Mineral a Mineral?

In order for something to be a mineral, it must first meet four criteria:

First, all minerals are solid. So, while water may contain minerals, water itself can’t be a mineral because it’s liquid.
Minerals are all naturally formed. This means they can’t be manufactured in a lab. Synthetic gems, like cubic zirconia, are therefore not minerals.
All minerals have a unique and specific chemical composition. This is like the DNA of the mineral – it’s what makes the mineral different from other minerals.
Lastly, all minerals have a crystalline structure. Minerals are some of the most beautiful substances on Earth, because they are always arranged in an orderly geometric pattern. Minerals of the same type always have the same geometric arrangement of their atoms.

Properties of Minerals

The Physical properties of minerals are used by Mineralogists to help determine the identity of a specimen. Some of the tests can be performed easily in the field, while others require laboratory equipment. For the beginning student of geology, there are a number of simple tests that can be used with a good degree of accuracy. The list of tests is in a suggested order, progressing from simple experimentation and observation to more complicate either in procedure or concept.

The following physical properties of minerals can be easily used to identify a mineral:

Color

Most minerals have a distinctive color that can be used for identification. In opaque minerals, the color tends to be more consistent, so Learning the colors associated with these minerals can be very helpful in identification. Translucent to transparent minerals have a much more varied degree of color due to the presence of trace minerals. Therefore, color alone is not reliable as a single identifying characteristic.

Streak

Streak is the color of the mineral in powdered form. Streak shows the true color of the mineral. In large solid form, trace minerals can change the color appearance of a mineral by reflecting the light in a certain way. Trace minerals have little influence on the reflection of the small powdery particles of the streak.

The streak of Metallic Minerals tends to appear dark because the small particles of the streak absorb the light hitting them. Non-metallic particles tend to reflect most of the light so they appear lighter in color or almost white.

Because streak is a more accurate illustration of the mineral’s color, streak is a more reliable property of minerals than color for identification.

Hardness

Hardness is one of the better properties of minerals to use for identifying a mineral. Hardness is a measure of the mineral’s resistance to scratching. The Mohs scale is a set of 10 minerals whose hardness is known. The softest mineral, talc, has a Mohs scale rating of one. Diamond is the hardest mineral and has a rating of ten. Softer minerals can be scratched by harder minerals because the forces that hold the crystals together are weaker and can be broken by the harder mineral.

The following is a listing of the minerals of the Mohs scale and their rating:

Talc
Gypsum
Calcite
Fluorite
Apatite
Orthoclase Feldspar
Quartz
Topaz
Corundum
Diamond

Cleavage & Fracture

Minerals tend to break along lines or smooth surfaces when hit sharply. Different minerals break in different ways showing different types of cleavage.

Cleavage is defined using two sets of criteria. The first set of criteria describes how easily the cleavage is obtained. Cleavage is considered perfect if it is easily obtained and the cleavage planes are easily distinguished. It is considered good if the cleavage is produced with some difficulty but has obvious cleavage planes. Finally it is considered imperfect if cleavage is obtained with difficulty and some of the planes are difficult to distinguish.

The second set of criteria is the direction of the cleavage surfaces. The names correspond to the shape formed by the cleavage surfaces: Cubic, rhombohedral, octahedral, dodecahedral, basal or prismatic. These criteria are defined specifically by the angles of the cleavage lines as indicated in the chart below:

Cleavage Type Angles

Cubic Cleaves in three directions @ 90o to one another Rhombohedral Cleaves in three directions but not @ 90o to one another Octahedral Cleaves in four directions Dodecahedral Cleaves in six directions Basal Cleaves in one direction Prismatic Cleaves in two directions

Fracture describes the quality of the cleavage surface. Most minerals display either uneven or grainy fracture, conchoidal (curved, shell-like lines) fracture, or hackly (rough, jagged) fracture.

Crystalline Structure

Mineral crystals occur in various shapes and sizes. The particular shape is determined by the arrangement of the atoms, Molecules or ions that make up the crystal and how they are joined. This is called the crystal lattice. There are degrees of crystalline structure, in which the fibers of the crystal become increasingly difficult or impossible to see with the naked eye or the use of a hand lens. Microcrystalline and cryptocrystalline structures can only be viewed using high magnification. If there is no crystalline structure, it is called amorphous. However, there are very few amorphous crystals and these are only observed under extremely high magnification.

Transparency or Diaphaneity

Diaphaneity is a mineral’s degree of transparency or ability to allow light to pass through it. The degree of transparency may also depend on the thickness of the mineral.

Tenacity

Tenacity is the characteristic that describes how the particles of a mineral hold together or resist separation. The chart below gives the list of terms used to describe tenacity and a description of each term.

Magnetism

Magnetism is the characteristic that allows a mineral to attract or repel other magnetic materials. It can be difficult to determine the differences between the various types of magnetism, but it is worth knowing that there are distinctions made.

Luster

Luster is the property of minerals that indicates how much the surface of a mineral reflects light. The luster of a mineral is affected by the brilliance of the light used to observe the mineral surface. Luster of a mineral is described in the following terms:

Metallic The mineral is opaque and reflects light as a metal would.Submettalic The mineral is opaque and dull. The mineral is dark colored.Nonmettalic The mineral does not reflect light like a metal.

Nonmetallic minerals are described using modifiers that refer to commonly known qualities.

Waxy The mineral looks like paraffin or wax.Vitreous The mineral looks like broken glass.Pearly The mineral appears iridescent, like a pearl.Silky The mineral looks fibrous, like silk.Greasy The mineral looks like oil on water.Resinous The mineral looks like hardened tree sap (resin).Adamantine The mineral looks brilliant, like a diamond.

Odor

Most minerals have no odor unless they are acted upon in one of the following ways: moistened, heated, breathed upon, or rubbed.

Taste

Only soluble minerals have a taste, but it is very important that minerals not be placed in the mouth or on the tongue. You should not test for this property in the classroom.

Specific Gravity

Specific Gravity of a mineral is a comparison or ratio of the weight of the mineral to the weight of an equal amount of water. The weight of the equal amount of water is found by finding the difference between the weight of the mineral in air and the weight of the mineral in water.

Minerals are naturally occurring, inorganic, solid substances with a definite chemical composition and crystal structure. They are essential to life on Earth, and are used in a wide variety of products, including building materials, electronics, and jewelry.

There are over 4,000 known minerals, but only a few are common. The most common minerals are quartz, feldspar, and mica. These minerals are found in rocks, which are aggregates of minerals.

Minerals are classified into two main groups: inorganic and organic. Inorganic minerals are formed by non-living processes, such as the cooling of magma or the weathering of rocks. Organic minerals are formed by living organisms, such as Plants and animals.

Minerals are further classified into groups based on their chemical composition and crystal structure. The most common mineral groups are oxides, carbonates, silicates, and sulfides.

Oxides are minerals that contain Oxygen and one other element. The most common oxide minerals are quartz, hematite, and magnetite.

Carbonates are minerals that contain carbon and oxygen. The most common carbonate minerals are calcite, dolomite, and limestone.

Silicates are minerals that contain silicon and oxygen. The most common silicate minerals are quartz, feldspar, and mica.

Sulfides are minerals that contain sulfur and one other element. The most common sulfide minerals are pyrite, galena, and sphalerite.

Minerals are important to humans in many ways. They are used in building materials, such as concrete and brick. They are also used in electronics, such as semiconductors and batteries. And they are used in jewelry, such as diamonds and rubies.

Minerals are also important to the Environment. They are a part of the Earth’s crust, and they help to regulate the Climate. They are also a part of the water cycle, and they help to purify water.

Minerals are a vital part of our world. They are used in a wide variety of products, and they are important to the environment. We should learn more about minerals and how to use them wisely.

Here are some additional facts about minerals:

The oldest known mineral is zircon, which is over 4.4 billion years old.
The largest known mineral is the Great Salt Lake in Utah, which is over 200 miles long and 50 miles wide.
The most valuable mineral is diamond, which can sell for up to $100,000 per carat.
The rarest mineral is californium, which is only found in trace amounts in nature.
The most abundant mineral is quartz, which makes up about 12% of the Earth’s crust.
The most common mineral in the human body is calcium, which makes up about 1.5% of our body weight.
Minerals are essential for life. They are used in the construction of bones and teeth, and they are involved in many important bodily functions, such as nerve function and muscle contraction.
Minerals are also used in a wide variety of products, including building materials, electronics, and jewelry.
The mining of minerals can have a negative impact on the environment. It can lead to deforestation, Soil erosion, and Water Pollution.
It is important to use minerals wisely and to recycle them when possible.

What is a rock?
A rock is a solid aggregate of one or more minerals or mineraloids.

What are the three main Types of Rocks?
The three main types of rocks are igneous, sedimentary, and metamorphic.

What are the three main types of minerals?
The three main types of minerals are silicates, oxides, and sulfides.

What is the most common mineral on Earth?
The most common mineral on Earth is quartz.

What is the most valuable mineral on Earth?
The most valuable mineral on Earth is gold.

What is the hardest mineral on Earth?
The hardest mineral on Earth is diamond.

What is the softest mineral on Earth?
The softest mineral on Earth is talc.

What is the most abundant element in the Earth’s crust?
The most abundant element in the Earth’s crust is oxygen.

What is the most abundant element in the Earth’s mantle?
The most abundant element in the Earth’s mantle is oxygen.

What is the most abundant element in the Earth’s core?
The most abundant element in the Earth’s core is iron.

What is the difference between a mineral and a rock?
A mineral is a naturally occurring, inorganic solid with a definite chemical composition and an ordered Atomic structure. A rock is an aggregate of one or more minerals or mineraloids.

What are the seven crystal systems?
The seven crystal systems are cubic, tetragonal, hexagonal, orthorhombic, monoclinic, triclinic, and trigonal.

What are the four main types of gemstones?
The four main types of gemstones are diamonds, rubies, sapphires, and emeralds.

What is the difference between a gemstone and a mineral?
A gemstone is a mineral that is prized for its beauty and rarity. A mineral is a naturally occurring, inorganic solid with a definite chemical composition and an ordered atomic structure.

What are the three main types of ores?
The three main types of ores are metal ores, non-metal ores, and fuel ores.

What is the difference between an Ore and a mineral?
An ore is a mineral that is economically important because it contains a valuable metal or other element. A mineral is a naturally occurring, inorganic solid with a definite chemical composition and an ordered atomic structure.

What are the three main types of mining?
The three main types of mining are open-pit mining, underground mining, and quarrying.

What is the difference between open-pit mining and underground mining?
Open-pit mining is a type of mining in which the ore is extracted from the surface of the Earth. Underground mining is a type of mining in which the ore is extracted from beneath the surface of the Earth.

What is the difference between quarrying and mining?
Quarrying is a type of mining in which rocks and minerals are extracted from the Earth’s surface. Mining is a type of extraction of minerals from the Earth that involves the removal of rock or soil.

What are the environmental impacts of mining?
The environmental impacts of mining can include deforestation, soil erosion, water pollution, Air Pollution, and greenhouse gas emissions.

What are the social impacts of mining?
The social impacts of mining can include displacement of people, loss of livelihoods, and conflict.

What are the economic impacts of mining?
The economic impacts of mining can include job creation, tax revenue, and economic Growth.

Which of the following is not a mineral?
(A) Gold
(B) Diamond
(C) Water
(D) Salt
Which of the following is a mineral that is used in construction?
(A) Gold
(B) Diamond
(C) Quartz
(D) Salt
Which of the following is a mineral that is used in electronics?
(A) Gold
(B) Diamond
(C) Silicon
(D) Salt
Which of the following is a mineral that is used in jewelry?
(A) Gold
(B) Diamond
(C) Ruby
(D) Salt
Which of the following is a mineral that is used in food?
(A) Salt
(B) Sugar
(C) Pepper
(D) All of the above
Which of the following is a mineral that is used in cosmetics?
(A) Talc
(B) Mica
(C) Kaolin
(D) All of the above
Which of the following is a mineral that is used in medicine?
(A) Aspirin
(B) Calcium
(C) Iron
(D) All of the above
Which of the following is a mineral that is used in agriculture?
(A) Phosphate
(B) Potassium
(C) Nitrogen
(D) All of the above
Which of the following is a mineral that is used in Industry?
(A) Copper
(B) Iron
(C) Aluminum
(D) All of the above
Which of the following is a mineral that is used in construction?
(A) Sand
(B) Gravel
(C) Cement
(D) All of the above