A monoclinic mineral, Cu2 Fe2 (AsO4 )2 (OH)
4 .H2 O ; earthy to opaline; associated with olivenite in
copper deposits.
The process of making iron sponge from ore mixed with coal dust and heated
in vertical cylindrical retorts. Fay
A monoclinic mineral, (Ca,Ce,Th)(P,Si)O4 ; monazite group; an
intermediate member of a crystal-solution series between CePO4
(monazite) and CaTh(PO4 )2 (a synthetic compound).
A variety of sapropelic coal composed of a mixture of structureless humic
sapropel and algal remains. Also spelled tscheremchite. Tomkeieff
a. A fishing tool in the modified form of a horn socket. The lower end or
mouth is cut away on one side and resembles a scoop; because of its shape,
the device, as it is turned, works around and behind an object that has
become partly embedded in the wall of a borehole, thus engaging it where a
regular horn socket would fail. Long
b. A small hoist to facilitate car changing near the loader in a tunnel.
An empty car is either lifted above the track (to allow a loaded car to
pass beneath) or swung to one side free of the track.
See also:double-track portable switch
particularly for handling large cars. Nelson
c. In tunneling, a small traveling crane spanning tracks that transfers an
empty car to a parallel track so that a loaded one can be drawn from the
advancing end. Pryor, 3
d. A small derrick made up of a sheave on an A-frame, a winch and winch
line, and a hook. Usually mounted on a truck. Nichols, 2
A common term used on the color scale, generally given as about 1,382
degrees F (750 degrees C).
A hard, dense, dull to semivitreous, microcrystalline or cryptocrystalline
sedimentary rock, consisting dominantly of interlocking crystals of quartz
less than about 30 mu m in diameter; it may contain amorphous silica
(opal). It sometimes contains impurities such as calcite, iron oxide, and
the remains of siliceous and other organisms. It has a tough, splintery to
conchoidal fracture, and may be white or variously colored. Chert occurs
principally as nodular or concretionary nodules in limestone and
dolomites, and less commonly as layered deposits (bedded chert); it may be
an original organic or inorganic precipitate or a replacement product. The
term "flint" is essentially synonymous, although it has been used for the
dark variety of chert. See also:jasper; silexite. AGI
A type of silicification in which fine-grained quartz or chalcedony is
introduced into limestones, such as in the Tri-State mining district of
the Mississippi Valley. AGI
A monoclinic mineral, Pb2 V2 O7 ; occurs in small
crystals at the Mounana uranium mine, Gabon.
See:chessylite
A term commonly used for azurite. Syn:chessy copper
See also:azurite
Microcline feldspar found in Chester County, PA.
a. In anthracite only, coal small enough to pass through a square mesh of
1 to 1-1/8 in (2.54 to 2.86 cm), but too large to pass through a mesh of
5/8 in or 1/2 in (1.59 cm or 1.27 cm). Known as No. 5 coal.
b. Arkansas. Coal that passes through a 2-in (5.1-cm) round hole and over
a 1-in (2.5-cm) round hole. See also:anthracite coal sizes
A flat gem having a polished concave depression. CF:cuvette
Crossbedding that dips in different directions in superimposed beds,
forming a chevron pattern. Also called herringbone crossbedding; zigzag
crossbedding. Pettijohn, 1
A rubble-filled trench system in the slope of a railway cutting, laid out
in herringbone fashion and leading surface water into buttress drains
arranged along the line of steepest slope. Hammond
A fold with a sharp angular hinge and planar limbs of equal length.
Syn:zigzag fold
" Âç jé Ê2 k DICTIONARY TERMS:chews Scot. Coal loaded with a screening shovel; mi
[\B]chews[\N]
An opaque variety of andalusite containing black carbonaceous impurities
arranged in a regular manner so that a section normal to the longer axis
of the crystal shows a black Maltese cross. It has long been used for
amulets, charms, and other inexpensive novelty jewelry. Syn:cross-stone;
crucite; macle.
A rock formed by contact metamorphism of carbonaceous shale, characterized
by prominent cleavage or schistosity and the presence of conspicuous
chiastolite crystals in a fine-grained groundmass. AGI
An Alaskan term for fine gravel 1/2 in (1.27 cm) or less in diameter.
Cupellation assay, for gold content of barren cyanide solution. The gold
(and silver) is precipitated together with metallic lead as sponge on
aluminum. This metal is cupeled, and the gold prill is weighed.
Pryor, 3