By Chisom Ibemere
Norite is a type of igneous rock which is composed basically of the mineral orthopyroxene, along with plagioclase feldspar. It is a mafic rock, which means it has a high content of dark-colored minerals, such as pyroxene and/or amphibole. The term “norite” comes from the Norwegian word “nord,” meaning north, as it was first described in Norway.
Norite is a coarse-grained, basic igneous rock, similar to gabbro, but distinguished by its dominant presence of orthopyroxene (specifically hypersthene or bronzite) rather than clinopyroxene
Components of Norite minerals includes: Orthopyroxene, Plagioclase Feldspar, Magic minerals.
Orthopyroxene: This mineral is a type of pyroxene that crystallizes in the orthorhombic system. Common orthopyroxenes found in norite include hypersthene and bronzite.
Plagioclase Feldspar: Norite typically contains plagioclase feldspar, which is a group of aluminum silicate minerals. The specific type of plagioclase can vary, but it often falls within the range of labradorite to bytownite.
Mafic Minerals: In addition to orthopyroxene and plagioclase, norite may contain other mafic minerals like olivine and amphibole, depending on the specific geological conditions of its formation.
Norite form part of a larger family of rocks known as plutonic rocks or intrusive rocks. They form from the slow cooling and solidification of molten magma beneath the Earth’s surface. The slow cooling allows larger crystals to form, giving plutonic rocks a coarse-grained texture.
As an igneous rock, it is classified based on its mineral composition and texture. Norite is categorized within the broader category of gabbroic rocks. Gabbroic rocks, including norite, are characterized by their high content of dark minerals and are often associated with the deeper parts of the Earth’s crust.
Generally, norite is an igneous rock with a distinctive composition dominated by orthopyroxene and plagioclase feldspar. It is part of the plutonic rock family and is classified as a mafic rock within the gabbroic group.