Si2O7yksikkö

Si2O7yksikkö refers to a disilicate anion. The disilicate ion has the chemical formula Si2O76-. It is a polyatomic anion composed of two silicon atoms and seven oxygen atoms. In this structure, the two silicon atoms are linked by a single oxygen atom, forming a bridging oxygen. Each silicon atom is also bonded to three other oxygen atoms. These bridging oxygen atoms are a characteristic feature of the disilicate structure, distinguishing it from isolated silicate tetrahedra (orthosilicates).

Disilicates are found in various mineral structures. Examples include melilite group minerals such as åkermanite (Ca2MgSi2O7) and gehlenite (Ca2Al(AlSi)O7). In these minerals, the Si2O76- unit plays a crucial role in defining the crystal lattice. The bonding within the disilicate unit is primarily covalent between silicon and oxygen. The overall charge of the disilicate anion is -6, which is balanced by the positive charges of the cations in the mineral structure. The Si2O7yksikkö is a fundamental building block in understanding the chemistry and crystallography of certain silicate minerals.