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oscillation

Independent movement through a limited range, usually on a hinge.
Nichols, 1

oscillator plate

A thin slab of quartz which, by mechanical vibration, controls the
frequency of a radio transmitter. Hurlbut

oscillator quartz

Flawless quartz, which can be used in the manufacture of oscillator
plates.

oscillatory twinning

Repeated twinning in which a crystal is made up of thin lamellae
alternately in reversed position; polysynthetic twinning; found in some
feldspars. Syn:polysynthetic twinning

oscillatory zoning

Repetitious concentric compositional variation in minerals resulting from
cyclical changes in the chemical environment during crystal growth; e.g.,
garnet and plagioclase.

oscillogram

A record of phenomena observed on an oscillograph. ASM, 1

oscillograph

An instrument that renders visible, or automatically traces, a curve
representing the time variations of various phenomena. The recorded trace
is an oscillogram. AGI

oscilloscope

An instrument for showing visual representations of electrical outputs
from measuring devices. Hunt

osmite

See:iridosmine

osmium

The native element, Os; occurs in magmatic deposits in mafic and
ultramafic rocks and placers derived from them.

osmosis

The passage of a solvent through a membrane from a dilute solution into a
more concentrated one, the membrane being permeable to molecules of
solvent but not to molecules of solute. AGI

osteolite

A massive, earthy mineral (apatite) consisting of an impure, altered
phosphate.

ostracod

A minute crustacean with a bean-shaped bivalve shell completely enclosing
the body. AGI

otavite

A trigonal mineral, CdCO3 ; calcite group; associated with oxidized
base-metal ores.

other rock in place

As used in the Mining Law of 1872, means any rocky substance containing
mineral matter. Ricketts

other valuable deposits

Includes nonmetalliferous as well as metalliferous deposits.
Ricketts

otisca process

A process that uses an inert heavy liquid with a specific gravity between
that of coal and free mineral matter to separate coarse or fine-size coal
in a static bath or cyclone separator.

Otisca-T process

A selective agglomeration process under development, in which ultra-fine
grinding of the feed coal to 15 mu m releases almost all the associated
impurities prior to agglomeration with a low-molecular-weight hydrocarbon.
The agglomerant is then recovered and recycled.

Otto cycle

In a four-stroke internal combustion engine two complete revolutions of
the crankshaft correspond with the working cycle-inlet stroke (suction
downstroke of piston in cylinder); compression upstroke; explosion at peak
of compression followed by expansion of hot exploded gases on driving
downstroke; rising exhaust stroke to complete the cycle. Pryor, 3

Ouachita stone

See:novaculite

oued

See:wadi