An obsolete term for bityite.

An obsolete term for a saponite-rich material from near Bowling, Dumbarton, Scotland.

Bragg’s law describes the condition for an X-ray reflection (i.e., constructive interference) for crystalline materials and is given as n λ = 2 d sinθ, where n is the path difference between reflecting planes, which must be an integer for constructive interference, λ is the wavelength, d is the interplanar spacing, and θ is the glancing angle of incidence (reflection angle). In an X-ray diffraction experiment, the λ is known and is dependent on the X-ray source in use,θ is the measured quantity, and d is the parameter that is characteristic of the material under study. Thus, both n and d are unknowns. In practice, the order of the reflection n is fixed for the value of d for a specific plane hkl (and thus is included in the value) and, the use of d_hkl symbolizes this inter-relationship. Thus, the modified version of the Bragg equation is used in practice, which is given as: λ = 2 d_hkl sinθ.

An aluminum-rich dioctahedral mica that shows interlayer deficiency and limited substitutions of Al in the tetrahedral sites. It is a series name (Rieder et al., 1998) with a generalized composition of Na_0.65Al₂□Al_0.65Si_3.35O₁₀(OH)₂. Series names designate that additional research may be warranted.

An obsolete varietal term for clintonite.

One of 14 different types of space lattices (three dimensional arrays). The Bravais lattices are characterized by identipoints showing translational periodicity, and this periodicity can be used to define a (unit) cell. There are five basic lattice types [P, A (or B or C), F, I, and R]. When distributed over the crystal systems, the five basic types produce 14 space lattices.
Cf., identipoint, lattice, array

A poorly defined material, possibly illite and montmorillonite.

A construction material (usually red, yellow, or pastel in color, generally rectangular in shape) mainly composed of calcium silicate phases, after firing or drying clay. Recycled and milled bricks (brick-dust) are used as additives in the production of lime mortar.

A platy serpentine with an ideal composition of (Ni_1.75Al_1.0)(Si_1.5Al_0.5)O₅(OH)₄. Crystals are generally poorly crystalline mixtures of hexagonal and monoclinic polytypes. Poorly described, Al-rich material similar to a Ni analogue of amesite (referred to as “nimesite”) was redefined as brindleyite. Brindleyite is compositionally similar to berthierine because of the tetrahedral Si/Al ratio and structurally similar owing to the hexagonal and monoclinic polytype intergrowths. Brindleyite has been found in the Marmara bauxite deposit, Greece.
Cf., amesite, berthierine, garnierite, nepouite, pecoraite, pimelite, willemseite

A regularly ordered interstratification of a pyrophyllite-like layer and dioctahedral smectite-like layer in a ratio of 1:1 (Dong et al., 2002)
Cf., interstratification