silicon-oxygen tetrahedron

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Diagram showing two views of a closest-packed silicon-oxygen tetrahedron: a side view and a top view with overlapping blue oxygen atoms around a central yellow silicon atom, plus an expanded side view and a stick diagram for clarity.

silicon-oxygen tetrahedron

mineralogy

Also known as: silicate tetrahedron

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July 13, 2026

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Diagram showing two views of a closest-packed silicon-oxygen tetrahedron: a side view and a top view with overlapping blue oxygen atoms around a central yellow silicon atom, plus an expanded side view and a stick diagram for clarity. — Figure 13: Two views of a closest-packed representation of the silicon-oxygen tetrahedron.

The silicon-oxygen tetrahedron is the fundamental building block of all silicate minerals. It consists of one silicon atom bonded to four oxygen atoms, arranged like the points of a tetrahedron. These tetrahedral units can link together in various ways, forming different mineral structures.1

Nesosilicates have independent tetrahedrons.1
Sorosilicates feature double tetrahedral groups where two tetrahedrons share an oxygen atom, resulting in a Si₂O₇ unit.12
Cyclosilicates form rings of three, four, or six tetrahedrons.1
Inosilicates create single-chain structures by sharing two oxygen atoms per tetrahedron.1
Phyllosilicates have sheet structures where each tetrahedron shares one oxygen atom with three others.1
Tectosilicates form a three-dimensional network where each tetrahedron shares all its oxygen atoms, with formulas often being multiples of SiO₂.13

These structures, along with the types and locations of other atoms, determine the properties of silicate minerals, which make up about 95 percent of Earth's crust and upper mantle.1

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amphibole
Crystal structure
…silicate mineral structures is the silicon-oxygen tetrahedron (SiO₄)^4-. It consists of a central silicon atom surrounded by four oxygen atoms in the shape of a tetrahedron. The essential characteristic of the amphibole structure is a double chain of corner-linked silicon-oxygen tetrahedrons that extend indefinitely parallel to the c crystallographic axis,…
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…silicate mineral structures is the silicon-oxygen tetrahedron (SiO₄)^4-. It consists of a central silicon atom surrounded by four oxygen atoms in the shape of a tetrahedron. The essential characteristic of the amphibole structure is a double chain of corner-linked silicon-oxygen tetrahedrons that extend indefinitely parallel to the c crystallographic axis,…
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clay mineral
Imogolite and allophane
…make up an isolated SiO₄ tetrahedron as in orthosilicates, and such tetrahedrons make a planar array on the side of a gibbsite sheet. Because silicon-oxygen bonds are shorter than aluminum-oxygen bonds, this effect causes that sheet to curve. As a result, the curved sheet ideally forms a tubelike structure with…
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…make up an isolated SiO₄ tetrahedron as in orthosilicates, and such tetrahedrons make a planar array on the side of a gibbsite sheet. Because silicon-oxygen bonds are shorter than aluminum-oxygen bonds, this effect causes that sheet to curve. As a result, the curved sheet ideally forms a tubelike structure with…
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industrial glass
Properties of glass
Thus, tetrahedrally connected networks, such as those formed by silicates and illustrated in Figure 2, are more viscous than triangularly connected networks, such as those formed by borates. In silicates, the addition of network-modifying alkali ions would raise the concentration of nonbridging oxygens, and the resulting…
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Thus, tetrahedrally connected networks, such as those formed by silicates and illustrated in Figure 2, are more viscous than triangularly connected networks, such as those formed by borates. In silicates, the addition of network-modifying alkali ions would raise the concentration of nonbridging oxygens, and the resulting…
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mica
Crystal structure
…polymerized sheets of silica (SiO₄) tetrahedrons. Two such sheets are juxtaposed with the vertices of their tetrahedrons pointing toward each other; the sheets are cross-linked with cations—for example, aluminum in muscovite—and hydroxyl pairs complete the coordination of these cations (see figure). Thus, the cross-linked double layer is bound firmly, has…
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…polymerized sheets of silica (SiO₄) tetrahedrons. Two such sheets are juxtaposed with the vertices of their tetrahedrons pointing toward each other; the sheets are cross-linked with cations—for example, aluminum in muscovite—and hydroxyl pairs complete the coordination of these cations (see figure). Thus, the cross-linked double layer is bound firmly, has…
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phyllosilicate
… with a structure in which silicate tetrahedrons (each consisting of a central silicon atom surrounded by four oxygen atoms at the corners of a tetrahedron) are arranged in sheets. Examples are talc and mica. Three of the oxygen atoms of each tetrahedron are shared with other tetrahedrons, but no two…
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… with a structure in which silicate tetrahedrons (each consisting of a central silicon atom surrounded by four oxygen atoms at the corners of a tetrahedron) are arranged in sheets. Examples are talc and mica. Three of the oxygen atoms of each tetrahedron are shared with other tetrahedrons, but no two…
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mineral
Silicates
…all silicate structures is the silicon-oxygen (SiO₄)^4– tetrahedron. It is composed of a central silicon cation (Si⁴⁺) bonded to four oxygen atoms that are located at the corners of a regular tetrahedron. The terrestrial crust is held together by the strong silicon-oxygen bonds of these tetrahedrons. Approximately 50 percent ionic…
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…all silicate structures is the silicon-oxygen (SiO₄)^4– tetrahedron. It is composed of a central silicon cation (Si⁴⁺) bonded to four oxygen atoms that are located at the corners of a regular tetrahedron. The terrestrial crust is held together by the strong silicon-oxygen bonds of these tetrahedrons. Approximately 50 percent ionic…
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sorosilicate
… with structures that have two silicate tetrahedrons (each consisting of a central silicon atom surrounded by four oxygen atoms at the corners of a tetrahedron) linked together. Because one oxygen atom is shared by two tetrahedrons, the chemical formula contains Si₂O₇, as in melilite or hemimorphite.
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… with structures that have two silicate tetrahedrons (each consisting of a central silicon atom surrounded by four oxygen atoms at the corners of a tetrahedron) linked together. Because one oxygen atom is shared by two tetrahedrons, the chemical formula contains Si₂O₇, as in melilite or hemimorphite.
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