rockformingmineraaleja

Rockforming minerals are the primary building blocks of rocks. They are defined as the minerals that make up the bulk of igneous, metamorphic, and sedimentary rocks. While there are thousands of known minerals, only a relatively small group are considered rockforming. These minerals are generally abundant and stable under the conditions found within the Earth's crust.

The most common rockforming minerals belong to a few major mineral groups. Silicates are by far the most dominant, forming over 90% of the Earth's crust. This group includes feldspars, quartz, micas, pyroxenes, amphiboles, and olivine. Feldspars, particularly plagioclase and alkali feldspar, are the most abundant minerals in the crust. Quartz is another crucial silicate, known for its hardness and resistance to weathering. Carbonates, such as calcite and dolomite, are significant in sedimentary rocks like limestone and dolostone. Oxides, like hematite and magnetite, and sulfides, such as pyrite, are also important in certain rock types.

The specific combination and abundance of rockforming minerals in a rock are key to its classification and understanding its origin. For example, the presence of quartz and feldspar is characteristic of granite, while olivine and pyroxene are common in basalt. Studying these minerals provides geologists with insights into the temperature, pressure, and chemical conditions under which rocks formed and evolved.