A branch fault. A minor fault ending against a major fault. AGI
In Johannsen's classification of igneous rocks, any light-colored,
relatively rare mineral, or mineral occurring in small quantities, such as
apatite, muscovite, corundum, fluorite, and topaz. AGI
In metallurgy, diverse operations, such as storing in bins, conveying (by
conveyors, feeders, elevators, or pumps), sampling, weighing, reagent
feeding, and pulp distribution. Gaudin, 1
A method of supplementing the main ventilating current in a mine by using
a small fan to draw air from the main current and force it through canvas
or metal pipe to some particular place, such as the ends of drifts,
crosscuts, raises, entries, or other workings driven in a mine.
See also:air mover; exhaust ventilation; ventilation tubing;
forced auxiliary ventilation; overlap auxiliary ventilation; piped air;
reversible auxiliary ventilation; two-fan auxiliary ventilation.
Lewis
The theoretical amount of extractable aluminum oxide, Al2 O3
, present in a bauxite. The amount of alumina in a bauxite that is present
in a form that allows it to be extracted by a refining plant.
That part of the total energy that can be usefully employed. In a perfect
engine, that part which is converted to work. Strock, 2
a. Those constituents of a lime that enter into a desired reaction under
the conditions of a specific method or process. ASTM
b. Represents the total free lime (CaO) content in a quicklime or hydrate
and is the active constituent of a lime. It provides a mean of evaluating
the concentration of lime. Boynton
The rate at which a given source would deliver energy to a load having an
impedance that is the conjugate of the source impedance is designated as
the available power of that source. Hunt
The available power loss of a transducer connecting an energy source and
an energy load is the transmission loss measured by the ratio of the
source power to the output power transducer. Hunt
a. The vertical distance between the altitude of the original surface
after uplift and the level at which grade is first attained. AGI
b. The relief that is available for erosion.
The amount of silica present in a flux that is not slagged by impurities
in the flux itself. Newton, 1
A large mass of snow, ice, soil, or rock, or mixtures of these materials,
falling, sliding, or flowing very rapidly under the force of gravity.
Velocities may sometimes exceed 500 km/hr. AGI
Guardplates that prevent loose material from sliding into contact with the
wheels or tracks of a digging machine. Nichols, 1
Alternate spelling of aventurine.
a. A word used to describe the metallic spangled effect seen, in reflected
light, in aventurine and aventurine feldspar. A sort of schiller but more
scintillating.
b. A display of bright or strongly colored reflections from included
crystals in some translucent mineral specimens.
a. A glass containing opaque sparkling particles of foreign material,
which is usually copper or chromic oxide. With copper particles, it is
called gold aventurine, and with chromic oxide particles, it is called
chrome aventurine or green aventurine. A glass containing gold-colored
inclusions. Webster 3rd; AGI
b. A translucent quartz that is spangled throughout with scales of mica or
of some other mineral. Syn:aventurine quartz
c. As an adj., having the brilliant spangled appearance of aventurine.
Applied esp. to transparent or translucent quartz or feldspar containing
shiny inclusions. Webster 3rd; AGI
d. A variety of albite with reddish reflections from exsolved hematite in
certain planes. See also:goldstone
Orthoclase, albite, or oligoclase that is more or less transparent, with
fiery reflections from enclosed flat mineral particles, which are probably
hematite or goethite. Sunstone is aventurine oligoclase. Hess
A glass supersaturated with either iron, chromium, or copper oxide (or a
combination of the oxides) that is melted and cooled under controlled
conditions to cause the excessive oxides to crystallize, forming platelike
crystals or spangles. See also:goldstone
See:aventurine
See:assay value
Eng. A clause that, in granting leases of minerals (coal, ironstone, and
clay in particular), provides that lessees may, during every year of the
term, make up any deficiency in the quantity of coal, etc., stipulated to
be worked, so as to balance the dead or minimum rent.