Define the following terms.

(i) Mineral:
A mineral is a naturally occurring inorganic solid with a defined chemical composition and a crystalline structure. Minerals are the building blocks of rocks and are characterized by specific physical properties, such as hardness, color, luster, cleavage, and density. They can be composed of one or more elements and are formed through geological processes over long periods of time.

(ii) Ore:
An ore is a naturally occurring rock or mineral from which a valuable substance, usually a metal or an element, can be extracted economically. Ores typically contain high concentrations of the desired material, making their extraction and processing financially feasible. The extraction of metals from ores often involves various processes such as mining, milling, and smelting to obtain the final product in a usable form.

(iii) Gangue:
Gangue refers to the commercially valueless material that surrounds, accompanies, or is closely mixed with the ore in a mineral deposit. While the ore contains the desired substance (e.g., metal), gangue consists of minerals and rocks that have little or no economic value. During the extraction of metals from ores, gangue is usually separated from the ore and discarded, as it does not contribute to the production of the desired metal and may interfere with the extraction process.