Nephelinelike

Nephelinelike is a term used in mineralogy and petrology to describe minerals that share structural or compositional similarities with nepheline, a feldspathoid mineral. Nepheline itself has the chemical formula Na3KAl4Si4O16. Minerals described as nephelinelike are often related to nepheline by close chemical substitutions or by having a similar framework structure, though they are not strictly nepheline.

This similarity might manifest in a shared framework of interconnected (Si,Al)O4 tetrahedra. Substitutions within the chemical formula, such as variations in the proportions of sodium and potassium, or the presence of other alkali metals or divalent cations, can lead to the formation of nephelinelike phases. These variations often result in minerals with slightly different physical properties, such as melting point or refractive index, compared to pure nepheline.

The term is also applied in the context of synthetic materials, where researchers may create compounds that mimic the structure or properties of nepheline for various applications. Understanding nephelinelike materials is important in the study of igneous rocks, particularly those that are undersaturated in silica, where nepheline and related minerals are common. It also plays a role in materials science and geochemistry.