P.R.U. hand pump and densitometer
A dust sampling instrument comprising a D.V.P. Mark 11 pump with a swept
volume of 90 cm3 . A filter paper is inserted into a bridge
behind the inlet nozzle of the pump such that a circle of 1-cm diameter of
the filter paper is exposed to the dust. The dust, while passing through
the filter paper, produces a stain. The optical density of the stain is
determined photoelectrically in a densitometer by the light that falls
upon a galvanometer. The dust particle concentration is evaluated by a
calibration factor. Its main disadvantage is that it underestimates the
number of fine particles. Nelson
See:vivianite
See:hydrocyanic acid
Eng. Cornish miners' term for soft white clay. Also spelled pryan.
A lode in which the ore is mixed with gossan or flucan. Arkell
A pole that forms the prop of a hoisting gin and stands facing the
windlass. Webster 3rd
a. A sandstone. The term is equivalent to the Latin-derived term arenite.
AGI
b. A term formerly used in Europe for a fine-grained, fissile, clayey
sandstone. AGI
c. The metamorphic derivative of arenite. Etymol: Greek psammos, sand.
See also:psephite; pelite. Adj. psammitic. AGI
See:hartite
a. A sediment or sedimentary rock composed of large fragments set in a
matrix varying in kind and amount; e.g., talus, breccia, shingle, gravel,
and esp. conglomerate. The term is equivalent to the Latin-derived term
rudite. AGI
b. The metamorphic derivative of rudite. Etymol: Greek psephos, pebble.
See also:psammite; pelite. Adj: psephitic. AGI
A prefix meaning false or spurious. AGI
An upward buckling of the superficial layers of the ground due either to
changes in volume brought about by pedogenic processes or to some other
nontectonic cause. Challinor
A tetragonal mineral, Pb5 Cu4 Cl10 (OH)8 .2H
2 O ; indigo blue; occurs only in parallel growth on boleite, at
Boleo, Baja California, Mex. Also spelled pseudoboleite.
A partially dolomitized limestone, characterized by: a mottled appearance,
that gives the rock a texture mimicking that of a breccia; or by a
weathered surface that appears fragmental. It is produced diagenetically
by selective grain growth in which localized, patchy, and irregularly
shaped recrystallized masses of coarse calcite are embedded in a lighter
colored and less altered matrix of calcareous mud. AGI
An orthorhombic mineral, Fe2 (Ti,Fe)O5 ; resembles brookite;
occurs in cavities in andesites. See:brookite
Colors and color plays produced by physical optics as opposed to
chromophores; e.g., diffraction, dispersion, and scattering.
Syn:structural color
A rock that resembles, or may easily be mistaken for, a normal sedimentary
conglomerate. Examples include a crush conglomerate consisting of cemented
fragments that have been rolled and rounded nearly in place by orogenic
forces; a pebble dike; a sandstone packed with rounded concretions; and an
aggregate of rounded boulders produced in place by spheroidal weathering
and surrounded by clayey material. See also:crush conglomerate
AGI
Quartz pseudomorphous after crocidolite. Syn:tiger's-eye; hawk's-eye.
English
Composed of detrital crystalline grains little worn and solidly compacted
by siliceous or other mineral matrix, so as to resemble a true crystalline
rock.
Intergrowth of sulfide minerals that simulate eutectic texture in metals.
See also:graphic granite
Peat that in spite of its fibrous condition, is soft, noncoherent,
plastic, and on drying, shows great shrinkage. See also:fibrous peat;
amorphous peat. Tomkeieff
See:sphalerite