The gap is the greatest distance at which, under certain given conditions,
a priming cartridge is capable of initiating a receiving cartridge
(receptor). The same explosive is usually used both as primer and
receptor, although the gap distance in such a case will also be affected
by any change in strength that may occur in the explosive. The gap test
can be carried out with the cartridges unconfined or confined, for
example, in tubes, in air, or in water. The test gives, for example,
information about changes in the explosive due to aging, moisture,
temperature, etc. Fraenkel
a. A type of spotted slate characterized by concretionary spots whose
shape resembles that of a caraway seed. Etymol: German.
CF:fleckschiefer; fruchtschiefer. AGI
b. See:feather amphibolite
A swing and hammer crusher, the hammers being pieces hung from trunnions
between two disks keyed to a shaft. When revolved, centrifugal force
throws the hammers out against the feed and a heavy anvil inside the
crusher housing. Liddell
A hexagonal mineral, NaCaY(F,Cl)6 ; in albitized granites and
associated quartz-microcline veins in Kazakhstan.
A Brazilian term used in the plateau region of Bahia for a comparatively
coarse, clay-cemented, ferruginous conglomerate in which diamonds are
found. AGI
a. A channel fixed around the lining within a shaft in order to catch the
water draining down the shaft walls and conduct it by pipes or water boxes
to a lower level. Also called water curb; water garland.
See also:water ring
b. A frame to heighten and increase content of a truck. CTD
a. A group of isometric minerals having the general formula A3 B
2 (SiO4 )3-2Dx (OH)4x in which A=(Ca,Fe,Mg,Mn)
and B=(Al,Cr,Fe,Mn,Si,Ti,V,Zr) with Si partly replaced by (Al,Fe).
b. The silicate minerals almandine, andradite, calderite, goldmanite,
grossular, hibshite, katoite, kimzeyite, knorringite, majorite, pyrope,
schlorlomite, spessartine, and uvarovite. Syn:granat
a. A term applied to the most common doublet, that with a very thin top of
red garnet, regardless of the color of the doublet.
b. Any doublet of dark red color regardless of whether any portion of it
is garnet, more correctly called a garnet-top doublet.
c. A composite stone made with a garnet top on a glass base. Also called
garnet-top doublet, garnet-topped doublet.
A metamorphic rock consisting chiefly of an aggregate of interlocking
garnet grains. CF:tactite
Introduction of, or replacement by, garnet. This process is commonly
associated with contact metamorphism. AGI
A light-green variety of grossular garnet closely approaching fine jadeite
in appearance, esp. that in Transvaal, South Africa.
A group of nonsilicate minerals that are isostructural with garnet,
including the oxide yafsoanite, the arsenates berzeliite and
manganberzeliite, and the halide cryolithionite. CF:hydrogrossular;
hydrogarnet.
A general term for hydrous nickel silicates. Syn:genthite; noumeite.
A monoclinic mineral, Ba3 NaSi2 B7 O16 (OH)
4 ; in colorless crystals associated with nahcolite and shortite in
core from an oil boring at Ouray, CO.
An orthorhombic mineral, Na2 Ca5 Al12 Si20 O
64 .27H2 O ; zeolite group; pseudotetragonal; forms radiating
aggregates in amygdules in basalts, commonly associated with other
zeolites, e.g., chabazite, thomsonite, and levyne; at the Garron Plateau,
County Antrim, Ireland, and 22 localities in eastern Iceland.
a. Combustible gases (methane), a mixture of air and combustible gases, or
other explosive gaseous mixture encountered in mining.
b. A fluid of low density and of high compressibility. The specific
recognition of a gas as distinct from a liquid of the same composition
requires the simultaneous presence of both phases at equilibrium.
See also:fluid; vapor. AGI
c. In mining, a mixture of atmospheric air with combustible gases.
Standard, 2
d. The term normally used by miners to designate any impure air, esp.
explosive combinations. BCI
e. The term generally applied to denote combustible gases. BS, 8
f. Any aeriform liquid other than atmosphere air, such as gaseous carbon
dioxide (blackdamp), carbon monoxide (whitedamp), methane (combustible
gases), and the common combustible petroleum-product gases.
CF:acetylene
g. Abbrev. for gasoline. See also:manufactured gas; natural gas.
Long
h. A fluid (as air) that has neither independent shape nor volume but
tends to expand indefinitely. A substance at a temperature above its
critical temperature and therefore not liquefiable by pressure alone.
Webster 3rd
i. As a verb, to affect or to treat with gas. To subject to the action of
gas. Webster 3rd
Device or signal system that warns underground workers of dangerous
concentration of combustible gases. Pryor, 3
An analysis of mine air to give information regarding the oxygen content
of the air and the presence of explosive or otherwise undesirable gas or
gases. It is a valuable aid in following the changes in mine air during
fires and after explosions. Lewis
a. Round inclusion in glass, synthetic corundum, and spinel, which reveal
their difference from native corundum, spinel, and most other native
gemstones, in which inclusions are negative crystals.
Syn:glass enclosure; gas enclosure.
b. Relatively rare type of fluid inclusions created where a gas such as
carbon dioxide is trapped in minerals growing from gas-saturated or
boiling liquids, identified by their tubular gas-filled structures.
The introduction of carbon into the surface layers of mild steel by
heating in a current of gas high in carbon--usually hydrocarbons or
hydrocarbons and carbon monoxide. CTD
A method of isotope separation in which heavy atoms are separated from
light atoms by centrifugal force. Lyman