K2Si4O9

K2Si4O9 is an inorganic compound that belongs to the family of potassium silicates. It consists of silicate tetrahedra linked in a tetrasilicate framework that is charge-balanced by potassium ions. The structural unit is based on SiO4 tetrahedra connected to yield the [Si4O9] framework, with potassium cations occupying interstitial sites to maintain overall electrical neutrality. In this sense, K2Si4O9 can be viewed as a salt formed from a polymerized silicate anion and potassium.

The material is typically prepared by high-temperature solid-state synthesis from silica and potassium oxide or carbonate, often followed by crystallization from a silicate melt. It can also be obtained by dehydration of hydrated potassium silicate precursors. K2Si4O9 is primarily of academic interest and is not a common mineral in nature; it is mainly encountered as a synthetic phase in laboratory studies of alkali silicates or as a component in glass-ceramic research.

Physically, reported samples of K2Si4O9 are described as colorless to white crystalline solids. Like other alkali silicates, its stability is governed by ambient conditions, with higher-temperature conditions leading to potential phase transformations into other potassium silicate forms. In practice, the compound serves as a model system for studying silicate polymerization and as a precursor material in the preparation of more complex alkali silicate ceramics and glasses.

Safety considerations for handling K2Si4O9 align with standard practices for inorganic powders: avoid inhalation of dust and minimize contact with skin and eyes.