tektosilikát

Tektosilikát is a term used in geology and mineralogy to describe a group of silicate minerals. These minerals are characterized by their crystal structure where the silicon-oxygen tetrahedra are interconnected in a three-dimensional network. In this structure, every silicon atom is bonded to four oxygen atoms, and each oxygen atom is bonded to two silicon atoms. This arrangement results in a framework where the ratio of silicon to oxygen is 1:2.

Common examples of tektosilikáty include quartz, feldspar, and nepheline. Quartz, with its chemical formula SiO2, is a prime example of a pure tektosilikát. Feldspars are a group of aluminosilikates, with general formulas like KAlSi3O8 (orthoclase) and NaAlSi3O8 (albite), where aluminum atoms substitute for some silicon atoms within the framework. Nepheline, a sodium-aluminum silicate, also exhibits this characteristic tektosilikát structure.

The tektosilikát structure imparts significant properties to these minerals, such as hardness and a high melting point. These minerals are abundant in the Earth's crust and are major components of many igneous, metamorphic, and sedimentary rocks. Their stability and resistance to chemical weathering are also direct consequences of their strong, interconnected framework. Understanding the structure of tektosilikáty is crucial for comprehending the composition and properties of a vast array of geological materials.