Of minerals, a natural resemblance to the carving or engraving on precious
stones.
The sculpture of the Earth's surface by erosion. AGI
a. The art of engraving upon gems.
b. The descriptive science of engraved gems.
Eng. Good merchantable brand, as applied to metal on the Metal Exchange.
Fay
A hexagonal mineral, (Na2 ,Ca)Al2 Si4 O12 .6H
2 O ; zeolite group; forms transparent to translucent, pyramidal or
tabular crystals, with other zeolites, in the amygdules of basaltic lava.
See:Geiger-Mueller tube.
A foliated rock formed by regional metamorphism, in which bands or
lenticles of granular minerals alternate with bands or lenticles in which
minerals having flaky or elongate prismatic habits predominate. Generally
less than 50% of the minerals show preferred parallel orientation.
Although a gneiss is commonly feldspar- and quartz-rich, the mineral
composition is not an essential factor in its definition. Varieties are
distinguished by texture (e.g., augen gneiss), characteristic minerals
(e.g., hornblende gneiss), or general composition and/or origins (e.g.,
granite gneiss). AGI
In a metamorphic rock, commonly gneiss, the coarse, textural lineation or
banding of the constituent minerals into alternating silicic and mafic
layers. Syn:gneissosity
a. That part of a mine from which the coal has been worked away and the
space more or less filled up with caved rock. See also:cundy
Fay
b. The refuse or waste left in the mine. Fay
Old workings.
a. A common term for goaf. Fay
b. To leave coal and other minerals that are not marketable in the mine.
Fay
c. To stow or pack any useless underground roadway with rubbish.
Fay
d. To store underground, as along one side of a working place, the rock
and refuse encountered in mining. Hudson
e. The space left by the extraction of a coal seam into which waste is
packed or the immediate roof caves. CTD
f. A pile of loose waste in a mine, or backfill waste packed in stopes to
support the roof. Ballard
g. Coal refuse left on the mine floor. Korson
h. The material so packed or stored underground. Hudson
i. To fill with goaf, or gob; to choke; as a furnace is gobbed, or gobs
up. See also:gobbing
a. Any device used for gobbing waste material. Jones, 1
b. A person employed to pack rubbish or waste into the gob. CTD
Trade name for a cutting machine provided with a conveyor for gobbing the
unusable cuttings formed during the cutting operation. Jones, 1
The act of stowing waste in a mine. Also called gobbing-up.
See also:gob
A thick layer of slate between two seams of coal. The lower seam is mined
and the upper seam and the slate are shot down; the coal is loaded out and
then the slate is gobbed. Fay
Cleaning up slate. Korson
See:gob pile
A wide entry with a heap of refuse or gob along one side.
a. Fire originating spontaneously from the heat of decomposing gob. Also
called breeding fire.
b. A fire occurring in a worked-out area, due to ignition of timber or
broken coal left in the gob. CTD
c. Fire caused by spontaneous heating of the coal itself, and which may be
wholly or partly concealed. See also:oxidation of coal;
spontaneous combustion. Mason
a. A roadway driven through the gob after the filling has settled.
CTD
b. Gob road.