dioctahedral structure

chemistry

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Dioctahedral structure refers to a type of octahedral sheet found in clay minerals. In these structures, two-thirds of the octahedral sites are occupied by trivalent cations, such as aluminum (Al³⁺). This contrasts with trioctahedral structures, where all octahedral sites are filled, typically by divalent cations like magnesium (Mg²⁺).1

The basic unit of clay minerals consists of tetrahedral and octahedral sheets. In dioctahedral minerals, the exposed surface of the octahedral sheet is composed of hydroxyls (OH⁻). A common example of a dioctahedral clay mineral is kaolinite, with the formula Al₂Si₂O₅(OH)₄. These structural arrangements are crucial for understanding the properties and behavior of various clay minerals.21

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clay mineral
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…called trioctahedral, and the latter dioctahedral. If all the anion groups are hydroxyl ions in the compositions of octahedral sheets, the resulting sheets may be expressed by M²⁺(OH)₂ and M³⁺(OH)₃, respectively. Such sheets, called hydroxide sheets, occur singly, alternating with silicate layers in some clay minerals. Brucite, Mg(OH)₂, and gibbsite,…
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…called trioctahedral, and the latter dioctahedral. If all the anion groups are hydroxyl ions in the compositions of octahedral sheets, the resulting sheets may be expressed by M²⁺(OH)₂ and M³⁺(OH)₃, respectively. Such sheets, called hydroxide sheets, occur singly, alternating with silicate layers in some clay minerals. Brucite, Mg(OH)₂, and gibbsite,…
Read More