See basal surface.

A diffraction X-ray peak from a layer material originating from those atomic planes which comprise the layers (i.e., parallel to cleavage). For most layer silicates, basal reflections are of the Miller index type: 00l, where l is an integer. The d values of the basal reflections may be used to obtain c Sin(beta), which is the repeat distance perpendicular to the plane of the layers. The c Sin(beta) value is usually an indicator of the structure unit and thus, the type of phyllosilicate, assuming that no semi-random interstratifications occur in the phase (which can cause a displacement of the basal reflection positions). For example, mica minerals have a value of about 10 A and chlorite minerals have a value of about 14 A.

The terminating surface (or basal plane) parallel to the atom planes in the repeating layers in clays and layered minerals. Common usage has broadened the meaning to include (internal) surfaces that parallel the terminating surface. If the repeating layers have a stacking direction along [001], the c crystallographic axis, then the atom planes in the repeating layers are the (00l) planes (parallel to the plane containing the two lateral axes, a and b).
Syn., basal plane

A poorly defined material, possibly interstratified biotite and vermiculite.

An obsolete term describing a pseudomorph comprised of serpentine altered from a Mg-rich pyroxene.

A poorly defined material, possibly interstratified biotite and vermiculite.

A reaction vessel without inflow or outflow. Batch reactors are commonly used for sorption experiments and, less commonly, for mineral growth and dissolution experiments.
Cf., continuously stirred tank reactor, chemostat, plug flow reactor

Discredited name because it is a mixture of several phases.
See caryopilite

The rock term for an aluminum ore consisting of primarily hydrous aluminum oxides [gibbsite, Al(OH)₃; boehmite, AlO(OH); and diaspore AlO(OH)], often mixed with iron oxyhydroxides (goethite, FeO(OH), and hematite, Fe₂O₃), kaolinite, and small amounts of anatase (TiO₂). Most bauxite deposits result from weathering of a variety of Al-rich source rocks that are low in comparatively stable silicates. Bauxite deposits are related to paleo-tropical or subtropical climate rather than lithology, especially where long periods of tectonic stability permitted “deep and thorough” weathering of the precursor rock.
Cf., bauxitic clay

Clay material containing minerals rich in their bulk aluminum content (e.g., gibbsite, boehmite, diaspore). This material is used for making refractories or as an ore for aluminum metal.
See bauxite