frameworksilikaatteja

Frameworksilicates, also known as tectosilicates, represent a major group of silicate minerals characterized by a three-dimensional framework structure. In this structure, each silicon atom is bonded to four oxygen atoms, and each oxygen atom is shared by two silicon atoms. This arrangement results in a rigid, three-dimensional network of SiO4 tetrahedra. The overall charge of the framework is typically negative, and this negative charge is balanced by interstitial cations, which can include alkali metals like sodium and potassium, as well as alkaline earth metals like calcium and magnesium.

The most common and abundant group of framework silicates is the feldspar group. Feldspars are essential components of most igneous and metamorphic rocks and are also found in many sedimentary rocks. They exhibit a wide range of compositions and properties, influencing the texture and appearance of the rocks they form. Quartz, another prominent member of the framework silicates, is composed solely of SiO4 tetrahedra with no interstitial cations, making it a neutral framework. Its high hardness and chemical inertness make it important in many geological and industrial applications. Other significant framework silicates include the feldspathoids, which have a similar framework structure to feldspars but with a lower silicon-to-oxygen ratio and are typically found in silica-undersaturated igneous rocks. The strong and interconnected nature of the framework gives these minerals generally high hardness and melting points.