a. Term that includes quarries for aggregate and quarries for the
production of limestone for industrial and agricultural purposes.
Streefkerk
b. Not owned or controlled by consumer. Contrasted with a captive quarry.
Procedures intended to produce an accuracy such that if a large number of
samples are taken from a single lot of coal, 95 out of 100 test results
will be within + or - 10% of the average of these samples.
Mitchell
a. The gradual diminution of a substance to a fine powder or dust by
crushing, grinding, or rubbing; specif., the reduction of a rock to
progressively smaller particles by weathering, erosion, or tectonic
movements. AGI
b. The breaking, crushing, or grinding by mechanical means of stone, coal,
or ore, for direct use or further processing. Syn:pulverization;
trituration. AGI
See:banded coal
See:orthoclase
Change in concentration of an ion in a saturated solution through addition
of another electrolyte that yields an ion in common with the solid
substance present in excess. The ion product remains constant, but with
the increase of concentration of one ion that of the other diminishes
correspondingly. Since the solution is already saturated, precipitation
occurs, the effect being a reversal of the process of ionization.
Pryor, 3
Lead (Pb) having four isotopes (mass numbers 204, 206, 207, and 208) in
the proportions generally obtained by analyzing lead from rocks and lead
minerals that are associated with little or no radioactive material;
commonly considered to be the lead present at the time of the Earth's
formation, as distinguished from lead produced later by radioactive decay.
AGI
See:muscovite
Opal without play of color. Most varieties are of no gemological interest
or importance; others because of their color or markings are set in
jewelry. CF:precious opal
See:pyrite
A colorless or white crystalline compound consisting of sodium chloride
NaCl , occurring abundantly in nature as a solid mineral (halite), or in
solution (constituting about 2.6% of seawater), or as a sedimentary
deposit (such as in salt domes and beds or as a crust around the margin of
a salt lake). See also:halite; rock salt; salt.
Electric current of constant strength of which the direction of flow is
reversed at constant intervals of time. Schieferdecker
Measurement of soil or rock after it has been placed and compacted in a
fill. Nichols, 1
The curve showing the relationship between the density (dry unit weight)
and the water content of a soil for a given compactive effort.
Syn:moisture-density curve
Machines, such as rollers, to expel air from a soil mass and so achieve a
high density. Smooth-wheel rollers are best for gravels, sands, and
gravels-and-clay soils with reasonably high moisture contents.
Pneumatic-tired rollers are best for clays with reasonably high moisture
content, and sheepsfoot rollers are the best for clays with low moisture
content. See also:superficial compaction
A laboratory compacting procedure to determine the optimum water content
at which a soil can be compacted so as to yield the maximum density (dry
unit weight). The method involves placing (in a specified manner) a soil
sample at a known water content in a mold of given dimensions, subjecting
it to a compactive effort of controlled magnitude, and determining the
resulting unit weight (ASCE, 1958, term 74). The procedure is repeated for
various water contents sufficient to establish a relation between water
content and unit weight. The maximum dry density for a given compactive
effort will usually produce a sample whose saturated strength is near
maximum. Syn:moisture-density test
A rock so closely grained that no component particles or crystals can be
recognized by the eye. Nelson
Drilling done by a company on its property using its own equipment
operated by personnel working for the company. Long
a. In photographic mapping, a device for measuring accurately the two
rectangular coordinates of the image of a point on a photograph.
Seelye, 2
b. An apparatus facilitating comparison of test material with known
standard, or with other substances. A comparator miscroscope has a
duplicate optical system, so that the observer sees two fields
simultaneously (one with each eye). The Lovibond comparator has colored
disks that can be matched against colored liquids to give approximate pH
value, etc., using the same principle as with a set of pH color tubes in a
more permanent and compact style. Pryor, 3
Instrument in which color of test solution is compared with that of
reference cell or tinted glass slide. Also called colorimeter.
Pryor, 3
A small, right-angled prism placed in a front of a portion of the slit of
a spectroscope or a spectrograph for the purpose of reflecting light from
a second source of light into the collimator, so that two spectra may be
viewed simultaneously. CTD