oliviinimaisia

Oliviinimaisia is a term used in mineralogy and petrology to describe minerals that share structural or chemical similarities with olivine. Olivine itself is a magnesium iron silicate mineral with the chemical formula (Mg, Fe)2SiO4. It is a common constituent of the Earth's upper mantle and is also found in mafic and ultramafic igneous rocks.

Minerals considered oliviinimaisia often exhibit a framework or crystal structure that is related to the olivine structure, which is characterized by isolated SiO4 tetrahedra linked by octahedral cations. This can include variations in the types of cations present, such as manganese, nickel, or calcium, or substitutions within the silicate framework. For instance, some minerals might have a higher proportion of iron or magnesium compared to typical olivine, or they may incorporate other elements that do not fundamentally alter the overall olivine-like arrangement of atoms.

The term is not a formal mineral classification but rather a descriptive one used by geologists to group minerals that have a close resemblance to olivine. This resemblance can be important for understanding the geological processes that form these minerals and the environments in which they occur. For example, studying oliviinimaisia minerals can provide insights into the composition and evolution of magmas and metamorphic rocks. Their physical properties, such as hardness, color, and specific gravity, are often comparable to those of olivine due to their shared structural basis.