dioctahedral

dioctahedral

[‚dī‚äk·tə′hē·drəl]
(crystallography)
Pertaining to a crystal structure in which only two of the three available octahedrally coordinated positions are occupied.
(mathematics)
Having 16 faces.
References in periodicals archive ?
According to Greene-Kelly (1953), Lim and Jackson (1986), and Volzone (1991), small ions in the interlayer position move into the vacant octahedral sites in dioctahedral minerals after moderate heating.
Inhibited vermiculite is a common constituent of kaolinite-dominant soils and its occurrence could be attributed to alteration of dioctahedral mica that persists in deeper horizons of these soils.
The Greene-Kelly (1953) test differentiates dioctahedral smectites on the basis of the seat of layer charge.
Tsipursky SL, Drits VA (1984) The distribution of octahedral cations in the 2:1 layers of dioctahedral smectites studied by oblique-texture electron diffraction.
The montmorillonite is composed of dioctahedral smectites with predominantly octahedral substitution, while the saponite is composed of trioctahedral smectites with mainly isomorphous substitution of [Si.
The synthetic clay used for these studies was a dioctahedral three-layer tetrasilisic fluoromica (SOMASIF MAE) produced by CO-OP Chemical Co.
In soils literature this mineral is referred to by a variety of names including dioctahedral chlorite, chloritised vermiculite, and inhibited vermiculite (Norrish and Picketing 1983); in the present work we refer to this phase as pedogenic chlorite.
Surface formations around the pan basins of the southwestern Kalahari are Kalahari sands, whose clay fraction consists of muscovite and dioctahedral smectite, at least in the Otjomongwa area (Mees 2001).
This is possibly because, in an oxidising environment, the octahedral Fe is oxidised and imparts to the mineral a dioctahedral character, holding K more tenaciously (Rich 1972) because of short K-O distance and larger K H distance in dioctahedral mineral.
The dominant clay mineral was found to be dioctahedral montmorillonite with minor amounts of illite and kaolinite.
While MMT is a 2:1 phyllosilicate, rectorite has a 1:1 type of layer structure arranged regularly with an alternating dioctahedral mica layer and dioctahedral smectite layer.
Rich CI, Cook MG (1963) Formation of dioctahedral vermiculite in Virginia soils.