On what basis do geologists separate minerals into classes? (C)

Minerals are naturally occurring inorganic substances with specific chemical compositions and crystalline structures. They are the building blocks of rocks, and understanding their properties is essential in geology.

Geologists classify minerals into classes primarily based on their chemical composition. The primary criteria include the anionic complexes present in the mineral and the dominant elements in their chemical structure.

Based on the classification criteria mentioned above, we can outline some of the major mineral classes that geologists use to separate the minerals, such as: 1. Silicates: These minerals contain silica (SiO2) as their basic unit. Examples include quartz, feldspars, and micas. 2. Carbonates: These minerals contain the carbonate ion (CO3)^2- as their basic structural unit. Examples include calcite and dolomite. 3. Sulfates: Minerals in this class have the sulfate ion (SO4)^2- as their basic structural unit. Examples include gypsum and barite. 4. Halides: This class includes minerals with halide ions (Cl^-, Br^-, F^-, I^-) in their chemical composition. Examples are halite and fluorite. 5. Oxides and Hydroxides: Minerals in this class contain oxygen as the primary anion. Examples include hematite and magnetite. 6. Sulfides: These minerals contain the sulfide ion (S^2-) as their basic structural unit. Examples include pyrite and galena. 7. Phosphates, Arsenates, and Vanadates: Minerals in this class contain phosphate (PO4)^3-, arsenate (AsO4)^3-, or vanadate (VO4)^3- ions. Examples include apatite and vanadinite. 8. Native Elements: This class includes minerals composed of a single element, such as gold, silver, and copper.

Geologists separate minerals into classes mainly based on their chemical composition, focusing on the anionic complexes and the dominant elements present in the minerals' structure. This classification helps in understanding the formation, associations, and properties of these minerals, which is essential in studying rocks, and thus providing valuable information about Earth's history, resources, and processes.