The earth’s crust is composed of various minerals available in the rocks. Different metals are extricated from these minerals after legitimate refinement. They are an indispensable part of the lives of humans.

Mineral:

1. Geologists say minerals are homogeneous substances whose inner structure is well-defined. In nature, they occur in a wide range of forms, from the hardest diamond to the softest talcum.
2. Rocks: They are mixes of homogeneous substances called minerals. Some rocks such as limestone consist of a single mineral only but the majority of the rock consists of several minerals in varying proportions. 
3. A specific mineral that will be framed from a specific blend of components relies on the physical and chemical conditions, under which the material structures. This results in a broad range of colors, hardness, crystal forms, luster, and density of specific minerals.

Mode of Occurrence of Minerals: 

1. Extraction of minerals is done from “ores” (ore is a word which means minerals are accumulated in a mixture formed with other elements.)
2. The mineral substance of the ore must be inadequate concentration to make its extraction industrially feasible.
3. The mineral ores that may be mined with ease or not can be decided by the structure or by the sort of emergence.

Forms of Minerals

Igneous and Metamorphic Rocks:

1. Minerals in liquid or molten and gaseous forms, forcefully came upward from the cavities present towards the surface of the earth and took shapes. While coming up they cool and harden due to a decrease in temperature.
2. Tin, copper, zinc, and lead, among others, are a few of the metallic minerals found in veins and lodes.

Sedimentary Rocks: 

1. The formation of sedimentary rocks occurs due to the deposition, accumulation, and concentration of horizontal data. These rocks have various minerals present as beds or layers.
2. Due to large periods and great pressure and heat, there are some iron forms and coal that are found as concentrated. 
3. Another group of sedimentary minerals is inclusive of gypsum, potash salt, and sodium salt. They are made as an outcome of evaporation, especially in parched regions.

Surface Rock Decomposition and Soluble Constituent Removal:

A residue of weathered materials containing ores is left behind. This way is used to produce Bauxite.

Placer Deposits: 

• There are minerals that are found as alluvial deposits in sands on valley floors and the hill’s base
• Generally it contains minerals that are not corroded by water
• Among these minerals, gold, silver, tin, and platinum are the most valuable

Minerals in Ocean: 

1. Despite the vast amount of minerals found in ocean waters, most of them are too widely dispersed to have any economic value.
2. Magnesium, bromine, and the common salt come primarily from ocean waters.
3. The oceanic beds are also rich in manganese nodules.