A fine red variety of pyrope garnet. See also:pyrope
Coarsely crystalline halite, NaCl, resulting from evaporation of saline
water; in massive, fibrous, or granular aggregates; occurs as a nearly
pure sedimentary rock, as extensive beds, or in domes or plugs.
See also:common salt; salt.
The combined cuttings and residue from drilling and sedimentary rocks and
formations, commonly known as sand pumpings. Williams
A shaft made for sending down rock for filling the stopes, etc., generally
kept nearly full, the rock being trammed away as needed.
Standard, 2
A mineral expert. Mathews
A machine for loading broken rock. See also:shovel loader
Nelson
A silky variety of asbestos. Fay
a. A slide involving a downward and usually sudden and rapid movement of
newly detached segments of bedrock sliding or slipping over an inclined
surface of weakness, as a surface of bedding, jointing, or faulting, or
other preexisting structural feature. The moving mass is greatly deformed
and usually breaks up into many small independent units. Rockslides
frequently occur in high mountain ranges, as the Alps or Canadian Rockies.
AGI
b. The mass of rock moving in or moved by a rockslide. Also spelled rock
slide. Syn:rock slip
See:rockslide
A slope driven through rock strata.
See:mountain soap
Material filling fracture cleavages in coal, consisting of nonclay mineral
matter, probably deposited from solution, and sand, usually calcite or
gypsum. AGI
In the stonework industry, one who splits large blocks of building
granite, marble, and sandstone into slabs or smaller blocks, by drilling
holes into the stone and then driving wedges into them until the stone
breaks along the line of drilled holes. Also called rock breaker; rock
driller. See also:rock driller; quarryman. DOT
a. See:rock pressure
b. The problem of determining the stresses that exist in the Earth's crust
has long been of interest to engineers and geologists. Many mining
problems are directly concerned with stresses that may cause mine openings
to collapse. Two phases of occurrence of rock stresses are important: (1)
the stresses existing in the rock before the excavation of the mine
openings; i.e., the free field stress, and (2) the indirect stresses
caused by the mine openings. See also:free field stress
a. The formational temperature at depth. The rate of increase of
temperature with depth (the geothermal gradient) is highly variable over
the earth, but averages 25 degrees C/km. AGI
b. The temperature of the rock in a mine. Lewis
A tunnel, drift, or crosscut driven through rock, usually connecting one
coalbed with another; also through barren rock in metal mines.
A matrix of turquoise with small grains of turquoise embedded in it.
Fay
a. One of the three major groups of rocks: igneous, sedimentary,
metamorphic. AGI
b. A particular kind of rock having a specific set of characteristics. It
may be a general classification, e.g., a basalt, or a specific
classification, e.g., a basalt from a particular area and having a unique
description. AGI
c. The megascopically recognizable ingredients of coal rock; i.e.,
vitrain, clarain, durain, and fusain. See also:banded ingredient
See:debris
S. Afr. One (short) ton (0.9 t) of rock in place equals about 12 ft (super
3) (0.34 m3 ). Horizontally, therefore, the weight of an ore
reserve covering a claim over a stoping width of 3 ft (0.91 m) is 64,000
ft2 X 3 ft / 12 ft3 /st = 16,000 st (14,500 t) at 100%
payability. In case the vein dips downward, the resulting amount must be
divided by the cosine of the angle of dip. Beerman