An instrument that detects and measures ionizing radiation by observing
the electrical current created when radiation ionizes gas in the chamber,
making it a conductor of electricity. Lyman
The ratio of the product of the activities of the ions produced from a
given substance to the activity of the undissociated molecules of that
substance. See also:activity
Any radiation that directly or indirectly displaces electrons from the
outer domains of atoms; e.g., alpha, beta, or gamma radiation.
Lyman
The outer part of the Earth's atmosphere, beginning at an altitude of
about 25 miles (40 km) and extending to the highest parts of the
atmosphere: it contains several regions that consist of a series of
constantly changing layers characterized by an appreciable electron and
ion content. Webster 2nd
Separation of ions by filtering them through the intermediately sized
lattice of a suitable aluminosilicate zeolite, chosen to permit passage
only of undersized ions through its rigid structure. Pryor, 3
See:wuestite
A triclinic mineral, Pb10 Cu(CrO4 )6 (SiO4 )
2 (F,OH)2 ; forms a series with hemihedrite in which zinc
substitutes for copper; at the Sebarz Mine, northeast of Anarak, Iran.
The exhibition of interference colors from the surface or interior of a
mineral, caused by light interference from thin films or layers of
different refractive index. Labradorite and some other feldspars show it.
The tarnish on the surface of coal, copper pyrites, etc., is sometimes
iridescent. Adj. iridescent.
Said to be a native alloy of gold and iridium carrying 62.1% gold, 30.4%
iridium, 3.8% platinum, and 2.1% silver. Hess
An alloy usually containing 90% or more of platinum. The remaining
percentage is of iridium, which is necessary to produce an alloy
sufficiently stiff for use in gem mountings.
a. An isometric mineral, native Ir ; Mohs hardness, 6 to 7; sp gr, 22.2 if
pure; occurs native (>80% Ir) and alloyed with osmium (iridosmine) or
platinum in mafic to ultramafic rocks and derived alluvial deposits; in
rare arsenides and sulfides, such as irarsite (Ir,Ru,Rh,Pt)AsS ,
iridarsenite (Ir,Ru)As2 , and iridisite-beta (Ir,Cu)3 S (sub
8) ; placer deposits may include gold.
b. The most corrosion-resistant metal known. Symbol, Ir. It is mainly used
as a hardening agent for platinum. Handbook of Chemistry and Physics, 3
A natural alloy of iridium and osmium, (Ir,Os). Analyses show 43% to 77%
iridium, 17% to 49% osmium, and a little rhodium, ruthenium, platinum,
iron, and copper. Rhombohedral. Syn:osmite
A canary-yellow mineral, (UO2 )(Mo26+ O7
).3H2 O ; luster, vitreous; uneven fracture; does not fluoresce.
Syn:priguinite
Slate, shale, or rock loaded out from a colliery as coal. Pryor, 3
An assessment on mining stock. Fay
A transparent quartz crystal containing minute air-filled or liquid-filled
internal cracks that produce iridescence by interference of light. The
cracks may occur naturally or be caused artificially by heating and sudden
cooling of the specimen. Syn:firestone; rainbow quartz.
a. Iron-base materials not falling into the steel classifications.
See also:gray cast iron; ingot iron; malleable cast iron;
nodular cast iron; white cast iron; wrought iron. ASM, 1
b. Colloquially, all derrick and drilling equipment above the heads of the
workers on the drill platform. Long
c. Any ferrous metal tool or part that must be fished from a borehole.
Also called junk. Long
d. An isometric mineral, native alpha-Fe ; metallic steel gray to black;
sp gr, 7.3 to 7.9. Occurs as grains in basalt in Disko Island, Greenland;
in meteorites, and in placers on South Island, New Zealand; and in Oregon
and British Columbia. Nickel is commonly reported in iron in quantities up
to several percent; meteoric iron generally contains at least 5%, and up
to 25% to 65%, nickel. Because of the instability of iron under oxidizing
conditions and the abundance of oxygen in the Earth's crust and
atmosphere, practically all terrestrial iron occurs in the divalent
(ferrous) or trivalent (ferric) state combined with other metals and
nonmetallic elements in silicates, oxides, sulfides, etc.
e. Fourth most abundant element, by weight, making up the crust of the
Earth. Symbol, Fe. The most common ore is hematite, Fe2 O3 ,
from which the metal is obtained by reduction with carbon. Iron is the
cheapest and most abundant, useful, and important of all metals.
Handbook of Chemistry and Physics, 3
See:halotrichite
Finely divided antimony. Standard, 2
See:clay ironstone
A chemical sedimentary rock, typically thin-bedded and/or finely
laminated, containing at least 15% iron of sedimentary origin, and
commonly but not necessarily containing layers of chert. Various primary
facies (usually not weathered) of iron formation are distinguished on the
basis of whether the iron occurs predominantly as oxide, silicate,
carbonate, or sulfide. Most iron formation is of Precambrian age. In
mining usage, the term refers to a low-grade sedimentary iron ore with the
iron mineral(s) segregated in bands or sheets irregularly mingled with
chert or fine-grained quartz. CF:ironstone; jaspilite. Essentially
synonymous terms are itabirite; banded hematite quartzite; taconite;
quartz-banded ore; banded iron formation; calico rock; jasper bar.
AGI