Any rough material, either natural or artificial, that can be fashioned
into a jewel. CF:gemstone
Any mineral species that yields varieties with sufficient beauty and
durability to be classed as gemstones.
An illuminator used to observe inclusions and other imperfections in
gemstones effectively. Employs either a monocular or a binocular
microscope.
a. One who appraises gems. Also spelled gemmologist (U.K.).
b. One who has mastered gemology.
a. The science of gems. CF:gemmary
b. The study of fashioned minerals, their imitators and substitutes both
natural and synthetic, prized for their beauty and durability. It concerns
composition, structure, occurrence, origin, fashioning, and identification
of gems, some of which are minerals and some of organic origin, e.g.,
pearls. CF:descriptive gemology; determinative gemology.
a. A term used for those better qualities of fine pearl that possess a
rose or other particularly desirable orient. Does not include white pearl.
b. An iridescent pearl, perfectly spherical, with maximum luster of even
intensity, free from all visible blemishes, and of a decided and desirable
orient, such as pink rose.
A stick on the end of which a gem is cemented while being cut.
Standard, 2
a. A mineral or petrified material that, when cut and polished, can be
used in jewelry. Syn:precious stone
b. A term that includes pearl, amber, coral, jet, or any stone of any
variety of gem material, of sufficient beauty and durability for use as a
personal ornament. See also:decorative stone; gem material;
ornamental stone. Also spelled gem stone.
The variety of a mineral species that yields gemstones.
In beneficiation, smelting, and refining, one who directs and coordinates
all operations concerned with reducing ore to designated size. DOT
A general investigation of superficial deposits. The sampling procedure
may include augers, boreholes, and trial pits, and tests are made to cover
soil identification. This type of survey aims at establishing soil
profiles and locating areas requiring special investigation.
See also:detailed soil survey; preliminary soil survey. Nelson
All the crystals of the same mineral species that appear to have
crystallized at essentially the same time; e.g., if there are olivine
phenocrysts in a groundmass containing olivine, there are said to be two
generations of olivine. AGI
a. A source of electricity, esp. one that transforms heat or mechanical
work directly into electric energy, as opposed to a voltaic battery.
Standard, 2
b. A vessel, chamber or machine in which the generation of a gas is
effected, as by chemical action. Standard, 2
a. The origin or formation of a natural gem mineral.
b. In petrology, the origin and evolution of rocks based on field and
textural observation allied with laboratory analyses and experimental
studies. CF:petrogenesis
c. In mineralogy, the origin of stable phases in terms of pressure,
temperature, and composition of parent materials.
d. In ore deposits, determination of specific peculiar and exceptional
conditions under which economic minerals have been concentrated.
CF:metallogeny
Any classification based on manner of origin or line of descent. Genetic
classifications are set up to deal with fossils, rocks, and minerals.
Stokes
An artificial ruby. Fay
A filter utilized in coal-washing plants for the recovery of fine coal
particles.
Cylindrical tank with obtuse conical base around which raking gear moves
slowly, pushing settled sludge to a central discharge. In the body of the
tank hang radially mounted tube frames covered with filter cloths (socks).
These are connected with a central valve and timing mechanism, so set that
vacuum is applied for 1 to 10 min to remove filtrate, after which the
gathered solids are displaced by a brief flushback so that they fall to
the raking zone. Pryor, 3
An isometric mineral, Zn4 Be3 (SiO4 )3 S ;
forms series with danalite and with helvite; in carbonatites and alkaline
pegmatites.
See:garnierite
Said of deposits and coal seams with a dip of from 5 degrees to 25 degrees.
Stoces