Classification of minerals
According to their chemical composition and internal structure, minerals are classified into the following groups:
- Native elements: They are found in nature in its pure state, formed by a single chemical element. They are divided into metallic, non-metallic and semi-metallic. Some examples of native elements are gold, silver, platinum, sulfur, diamante.
- Halides: They are basically salts, formed by the combination of metals with halogens such as fluorine, chlorine, bromine and iodine. For example, halite (NaCl), which is the salt we use in cooking.
- Oxides: They are produced by combining metals with oxygen. For example, iron (hematite and magnetite), chromium (chromite), manganese (pyrolusite) or tin (cassiterite) minerals.
- Hydroxides are also included in this group, which usually appear as a product of weathering. For example, limonite (with iron).
- Sulfides: Formed by the union of sulfur with some metal. They are very important because they are the majority of mineral ores. Sulfides are pyrite (of iron), galena (of lead), sphalerite (of zinc) or cinnabar (of mercury).
- Carbonates: They are formed by carbonate (carbon and oxygen) and a metal. They are very abundant, such as calcite.
- Sulfates: In their composition they have sulfur and iron. Gypsum stands out for its economic importance.
- Phosphates: They are important because they are the most important source of phosphorus. The most important phosphate is apatite. Another phosphate, used in jewelry, is turquoise.
- Nitrates: They contain nitrogen. They are soluble in water, and are used as fertilizers in agriculture.
- Silicates: Its structure is formed mainly by silicon and oxygen atoms. One third of the known minerals belong to this group. They are the most abundant minerals in the earth's crust. Examples of silicates are quartz, feldspars, micas, olivine, etc.