A monoclinic and hexagonal mineral, FeS ; invariably deficient in iron;
variably ferrimagnetic; metallic; bronze yellow with iridescent tarnish;
in mafic igneous rocks, contact metamorphic deposits, high-temperature
veins, and granite pegmatites. Where associated with pentlandite and
nickel replaces iron, it is a source of nickel. Also spelled pyrrhotine.
Syn:magnetic pyrite; dipyrite.
The composition quadrilateral for the Ca-Mg-Fe pyroxenes
(enstatite-ferrosilite-diopside-hedenbergite).
A horizontal angle or bearing less than 90 degrees , measured to north,
south, east, or west from a survey line. Hammond
A machine that will make a shear cut as well as a horizontal cut. The
central column is wedged tightly between roof and floor and operates
similarly to a radial percussive coal cutter. Nelson
Similar to octant search, but using four sectors instead of eight sectors.
Applies to any interpolation method where a limited number of sample data
points are used to estimate intermediate values.
A four-sided plane figure of any shape, having an area equal to the
product of the diagonals multiplied by half the sine of the angle between
them. Hammond
See:crossed twinning
a. Having a valence of 4. Webster 3rd
b. Having four valences; e.g., chlorine, which has a valence of 1, 3, 5,
and 7. Handbook of Chemistry and Physics, 2
A pair of blocks, each having four sheaves, reeved with rope or cable and
used to increase the lifting capacity of a drill-hoisting mechanism; a
four-sheave block and tackle. Long
A soft marsh or bog that gives under pressure. CF:quaking bog
AGI
A well-defined bed resembling a slump sheet but produced by seismic shock
from an earthquake and resulting in load casting without horizontal slip.
AGI
A peat bog that is either floating or is growing over water-saturated
ground, so that it shakes or trembles when walked on. Quagmire is
sometimes used as a synonym. AGI
In chemistry, the process of determining which elements are present.
Standard, 2
a. Refers to the nature, and not the amount, of material. In the case of a
coal seam, its quality is closely linked with its rank and its chemical
composition. In the case of metals, average unit values are determined by
systematic sampling and therefore represent a known quantity.
See also:ventilation standards
b. Native values of a gem irrespective of color and cut. Hess
c. The ratio by weight of vapor to liquid plus vapor in a mixture, as in
steam. Strock, 2
a. Systematic setting, check, and operation designed to maintain steady
working conditions in continuous process such as mineral concentration; to
forestall trouble; to check condition of ore, pulp, or products at
important transfer points. Pryor, 3
b. Graphic method of exposing abnormalities in sets of figures produced by
measurement of repetitive operations or as variances from operating norms.
Pryor, 3
c. The maintaining of air within desired limits of purity.
Hartman, 1
Once a dust sample has been collected, it must be evaluated. Of principal
concern is quantitation--determining how much dust or how many particles.
Certain methods of quantitation are favored for the various sampling
methods. The number basis is preferable for evaluating a pulmonary hazard,
while the weight basis is preferred for toxic, radioactive, or explosive
hazards. Number quantitation is usually employed for impinger, konimeter,
molecular filter, and thermal precipitator samples. Weight quantitation is
used for filter paper and electrostatic samples. Hartman, 1
In testing ore, how much of each metal is present. von Bernewitz
In chemistry, the process of determining the quantity of each element
present. Also called elementary analysis. Both volumetric and gravimetric
methods are included. Standard, 2
Deals with the amount, and not the nature, of a substance. In the case of
a coal seam, quantity refers to its workable thickness and acreage. In the
case of ore, the quantity determines its commercial importance. Unit ore
values without the quantity factor have only a qualitative significance.
Nelson
The control of air movement, its direction, and its magnitude.
Hartman, 2