A short, adjustable-angle trough that permits turning the conveyor panline
any amount up to 30 degrees , either to the right or to the left. The
position of the swivel is controlled by a roof jack and a pendulum.
Jones, 1
A bench vise that may be rotated on its base to bring the work that it
holds into better position. Crispin
Pure, uncoined, lump silver of various sizes, usually stamped with a
banker's or assayer's seal; used by the Chinese as a medium of exchange
and reckoned by weight. The larger lumps, sometimes called shoes, are boat
shaped and weigh about 1 lb troy (370 g). Standard, 2
A group of plutonic rocks containing alkali feldspar (usually orthoclase,
microcline, or perthite), a small amount of plagioclase (less than in
"monzonite"), one or more mafic minerals (esp. hornblende), and quartz, if
present, only as an accessory; also, any rock in that group; the intrusive
equivalent of "trachyte." With an increase in the quartz content, syenite
grades into "granite." Its name is derived from Syene, Egypt. A.G. Werner
in 1788 applied the name in its present meaning; the Egyptian rock is a
granite containing much quartz.
A group of plutonic rocks intermediate in composition between syenite and
diorite, containing both alkali feldspar (usually orthoclase) and
plagioclase feldspar, commonly more of the former; also, any rock in that
group. Generally considered a syn. of monzonite, but may also include both
monzonite and rocks intermediate between monzonite and diorite
(Streckeisen, 1967). See also:monzonite
A plutonic rock differing in composition from gabbro by the presence of
alkali feldspar. AGI
Former name for native tellurium and for sylvanite.
a. A monoclinic mineral, 2[AuAgTe4 ] ; soft; metallic; commonly in
implanted crystals resembling written characters; sp gr, 8.1; in quartz
veins; a source of gold and silver. Also spelled silvanite.
Syn:graphic ore; graphic tellurium; white tellurium; yellow tellurium;
goldschmidtite.
b. An old name for native tellurium. Dana, 1
A hand-operated device for withdrawing supports from the waste or old
workings. The appliance enables a leverage of about 30 to 1 to be applied.
A long chain allows it to be positioned a safe distance from the support
to be extracted. It may also be used for applying tension or for moving
machines short distances. See also:tension end; monkey winch.
Nelson
A three-step method for the recovery of manganese and iron from
open-hearth slag and low-grade ores. Osborne
The name for potassium chloride found native in the salt deposits at
Stassfurt, Germany. See also:sylvite
A mining term for the mixtures of sylvite and halite occurring in the
Prussian salt deposits; mined as potassium ore. English; AGI
An isometric mineral, 4[KCl] ; cubic cleavage; bitter salty taste; soft;
white; in evaporite deposits and around fumaroles; the chief source of
potassium. Syn:sylvine; leopoldite.
Two or more organisms living together to the mutual benefit of both.
Rogoff
A diagram, design, letter, color hue, abbrev., or other graphic device
placed on maps, charts, and diagrams, that by convention, usage, or
reference to a legend is understood to represent a specific
characteristic, feature, or object, such as structural data, rock
outcrops, or mine openings. AGI
a. The mathematical expressions for designating the position of crystal
faces on coordinate axes. See also:Miller indices; plane.
b. Any sign or letter used in crystallography to designate a group of
smaller faces. AGI
In optical mineralogy, the dispersion that produces an interference figure
with color distribution symmetrical to the trace of the axial plane and
also to a line normal to it.
A fold whose limbs have the same angle of dip relative to the axial
surface. CF:asymmetric fold
See:split spread
a. Symmetry in crystallography results from periodic repetition. A
symmetry element is the geometrical locus about which a group of repeating
operations acts. It may be a center, a mirror plane, or a rotation axis.
b. A symmetry group is a collection of symmetry elements that may
intersect at a point (point group) or that may be distributed in
three-dimensional space (space group). See also:point group
c. The symmetry of a fabric is the combined symmetry of all the elements
making up the fabric. There are five possible symmetries: (1) spherical,
for fabrics having the symmetry of a sphere; (2) axial, for fabrics having
the symmetry of a spheroid; (3) orthorhombic, for fabrics having the
symmetry of a triaxial ellipsoid; (4) monoclinic, for fabrics having one
unique plane of symmetry; and (5) triclinic, for fabrics having no planes
of symmetry.
See:axis of symmetry; crystal axis.