Mineral Resources: Introduction, Definition and Uses

Key Concepts:

• Earth
• Metallic resources
• Non-metallic resources
• Minerals
• Ore
• Mining

Introduction: 

Earth has many natural resources, such as oil, water, soil, minerals, wind, and sunlight, which are distributed unevenly on Earth’s surface. It means the presence of resources is more in specific places because of the processes by which they form. For example, today, whatever fossil fuels are found are formed by different geologic processes. Each process took place in a particular location and under specific conditions. For example, most of the coal is formed where tropical swamps were present millions of years ago. Salt deposits were formed where seawater entered a shallow area, and as the water evaporated, the soluble materials were left behind, and layers of salt (mineral) formed. Most of the geologic processes took place over millions of years ago, and hence natural resources formed in these ways tend to be non-renewable. Some of the resources, such as wind and sunlight, are renewable resources. These resources are also limited in their distribution. Resources can be changed by the movement of geologic processes. Hence, all natural resources are not found where they were first formed. For example, rocks that contain gold can be raised and exposed to Earth’s surface. Weathering breaks down rock into smaller pieces, and erosion carries these sediments far away. As a result of this, gold gets carried away by water and found in streams downhill from the rock from where it came. Resources can also get changed by geologic processes. For example, mineral calcite, which is used in medicine and building materials, can be dissolved by water, and then placed in a new form in a different place. 

Mineral Resources 

A naturally occurring substance that has a definite chemical structure is called a mineral. Minerals are unevenly distributed on Earth. Minerals are found in large amounts in particular areas or in rock formations. Minerals are mined (extracted) and processed for a wide variety of uses. 

Minerals are extracted and processed for a wide range of uses. Minerals are used for making buildings, roads, electronics, and cosmetics. It may take millions of years for the formation of mineral deposits and tend to be non-renewable. All minerals are not found in their pure form. Many times, a mineral is mixed with other minerals present in the rock. From mineral deposits, metals and non-metals that can be removed are called ores. For example: Iron metal can be removed from naturally occurring deposits of magnetite and hematite. Iron ore is an iron-rich rock. Ores are processed to extract the required minerals from other minerals present in the rock. The processing method is based on the minerals present in the ore. Formation of minerals takes place by various processes and from different chemical building blocks. Therefore, mineral resources are distributed unequally on the Earth. The location of mineral deposits depends on the method of formation of minerals. For example: Metals like gold and silver are found in and close to the intrusive igneous rock. The formation of these deposits takes place when hot fluids carrying dissolved metals escape from molten rock or cooling magma. When the hot fluids cool, the dissolved particles of metals solidify and deposit in the nearby rocks. There are some geological methods such as dissolution, evaporation and contact with molten rock that changes the current minerals into new minerals, whereas the other geological methods such as erosion by wind, water, and uplift by the movement of tectonic plates can move the mineral from one place to other new places. 

Human Impact on Energy and Mineral Resources 

Resources like minerals and fossil fuels must be extracted from the ground before humans can use them. Extraction of resources results in changes in distribution because the resources are extracted and carried to a new place. For example: When oil is extracted or pumped out from the ground for the use of human beings, the quantity of oil in that reservoir reduces or can be completely depleted. As we know, once we use non-renewable resources and mineral resources, they cannot be replaced for millions of years. Once we extract and use non-renewable resources such as minerals and oil and energy resources, the availability of the total amount of mineral and energy resources declines for future use. 

As mineral deposits, reservoirs and energy resources get smaller and smaller, they disappear, so in that situation, we must find new deposits and reservoirs to use. The quality of these new deposits may be of lower quality or possibly more challenging to obtain than the original deposits. Modern technologies can be developed to extract resources. Some of the non-renewable resources can be recycled. For example: Gold can be obtained from the existing jewelry and used again for making other products like electronics. By recycling mineral resources, we can reduce the demand for mining and processing new ore deposits. We should reduce and manage the use of non-renewable resources such as minerals and fossil fuels to ensure the availability of these resources for future generations. 

Ores formed by cooling Magma 

There are variety of ways in which ores are formed. Some of the ores like ores of chromium, nickel and lead are formed in the cooling magma of Earth. When magma starts cooling, the heavy metallic minerals sink at the bottom. The layers of these sinked minerals collect at the bottom of the magma chamber to form the deposits of ore. 

Ores Formed by Contact Metamorphism 

Ores of lead, copper and zinc are formed by the process of contact metamorphism. The process of contact metamorphism occurs when magma comes in contact with the existing rock. The composition of the existing rock can change by heat and chemical reactions with hot fluids from the magma. These changes sometimes result in the formation of ores. 

Contact metamorphism also results in the formation of ore deposits when very hot fluids called hydrothermal solutions move through the small cracks or openings in the rocks. In this process, minerals present in the surrounding of rock get dissolved into hydrothermal solution. Over a period of time, new minerals precipitate and form narrow zones of rock called veins. Generally, veins consist of ores of gold, tins, Sn, lead, and copper. So, when in small regions, many thick mineral veins form, the ore deposit is called iode. 

Ores Formed by Moving Water 

Ore deposits are formed by the movement of water. In the beginning, the pieces of native elements such as gold are released from rock which is broken down by weathering. Then, moving water (Stream) carry these fragments until the speed of moving water becomes too weak to carry those pieces of metals. Lastly, due to the mechanical action of moving water (stream), the fragments settle at the bottom of the stream beds called placer deposits. 

Uses of Minerals 

Summary:

•  Humans depend on natural resources because humans use natural resources as sources of energy.
•  Earth’s many natural resources, such as oil, water, soil, minerals, wind, and sunlight, are distributed unevenly on Earth’s surface.
•  Resources can be changed by the movement of geologic processes.
•  A naturally occurring substance that has a definite chemical structure is called a mineral.
•  Minerals are extracted and processed for a wide range of uses.
•  Extraction of resources results in changes in distribution because the resources are extracted and carried to a new place.
•  Contact metamorphism results in the formation of ore deposits.
•  Ore deposits are formed by the movement of water.