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 Na0.65Al2□Al0.65Si3.35O10(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 (Ni1.75Al1.0)(Si1.5Al0.5)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
A descriptive term for tenacity where a mineral breaks easily with a lack of flexibility or elasticity.
A group name for platy phyllosilicates of 2:1 layer and a layer charge of ~ -2.0 per formula unit. Rieder et al. (1998) defines the brittle micas as having greater than 50% of the interlayer cations as divalent. Brittle micas do not have swelling capacity. Common divalent cations in the interlayer include Ca and Ba. The subgroups of the brittle micas are based on dioctahedral or trioctahedral character, and species within the subgroups are based on chemical composition.
Cf., mica, true mica, interlayer-deficient mica, group names
An obsolete varietal term for clintonite.