nesoszilikátokban

Nesoszilikátokban refers to minerals belonging to the nesosilicate group, a fundamental classification of silicate minerals. These minerals are characterized by their structural unit, which consists of isolated [SiO4]4− tetrahedra. In nesosilicates, these tetrahedra are not linked to each other, meaning each silicon atom is bonded to four oxygen atoms, and these [SiO4] groups are discrete units within the crystal structure. They are typically bonded to interstitial cations, such as magnesium, iron, calcium, aluminum, or beryllium, which occupy positions between the tetrahedra and hold the structure together.

This isolated tetrahedral structure often results in nesosilicates having relatively simple chemical formulas and distinct physical properties. Many nesosilicates are known for their hardness and density. Common examples of nesosilicate minerals include olivine ((Mg,Fe)2SiO4), which is a major component of Earth's upper mantle, garnet (a group of silicates with a general formula X3Y2(SiO4)3), zircon (ZrSiO4), and topaz (Al2SiO4(F,OH)2).

The occurrence of nesosilicates is widespread in various geological environments. Olivine, for instance, is prevalent in mafic and ultramafic igneous rocks. Garnets are found in both metamorphic and igneous rocks. Zircon is a very stable mineral commonly found in igneous, metamorphic, and sedimentary rocks, and is often used for radiometric dating due to its resistance to weathering. Topaz is typically found in granitic and rhyolitic igneous rocks, as well as in some metamorphic rocks. The unique structure of nesosilicates influences their optical and physical properties, making them important subjects of study in mineralogy and geology.