Ventilation by a current of air traveling in the opposite direction to
that of the flow of mineral out of the mine.
See also:ascensional ventilation; descensional ventilation;
homotropal ventilation. BS, 8
A system fitted to a drag suction hopper dredge which disperses entrained
gases from the overflow in a settling tank and discharges the degassed
overflow below the surface. The resulting plume is normally compact and
does not appear at the surface. Abbrev., ATOS. Cruickshank
An orthorhombic mineral, 4[Cu3 SO4 (OH)4 ] ; forms
emerald to blackish-green striated crystals or parallel aggregates; may be
reniform or massive; in oxidized parts of copper veins; an ore of copper
in desert regions. Syn:vernadskite
Mixture of ammonium nitrate and trinitrotoluene used as an explosive.
Lewis
See:eriochalcite
A dark-violet to black semiopaque variety of fluorite that emits a strong
odor when crushed; commonly causing nausea among miners, perhaps owing to
free fluorine; produced by alpha bombardment, as in the inner bands of
halos surrounding uraninite and thorite inclusions.
a. The stationary serrated jaw piece or plate of a safety clamp,
adjustable pipe wrench, or jaw-type rock crusher. Also sometimes
incorrectly used as a syn. for drive hammer. Also called anvil block;
anvil heel; anvil jaw; heel. Long
b. An iron block placed between a stamp-mill mortar box and the foundation
block; generally used in light mortars and concrete foundations.
Fay
c. In drop forging, the base of the hammer into which the sow block and
lower die part are set. ASM, 1
d. A block of steel upon which metal is forged. ASM, 1
A massive block of cast iron placed beneath the anvils of steam and other
heavy hammers to absorb vibration. It is often embedded in masonry or
concrete. Crispin
See:anvil
Eng. Blue building stone, forming a bed of irregular anvil-shaped blocks.
Arkell
A vise with an anvil on one jaw. Standard, 2
See:zincite
A hydrous ferric sulfate, found in yellow nodules in clay. Fay
a. Any hexagonal or monoclinic pseudohexagonal mineral with the general
formula A5 (XO4 )3 (F,Cl,OH) , where A =
(Ba,Ca,Ce,K,Na,Pb,Sr,Y) and X = (As,C,P,Si,V). Syn:calcium phosphate
b. A mineral group fluorapatite, chlorapatite, hydroxylapatite,
carbonate-fluorapatite (francolite), and carbonate-hydroxylapatite
(dahllite).
a. The highest point of a vein relative to the surface, whether it crops
out or not. The concept is used in mining law. See also:apex law
AGI
b. The tip, summit, or highest point of a landform, as of a mountain;
specif. the highest point on an alluvial fan, usually the point where the
stream that formed the fan emerged from the mountain or from confining
canyon walls. Syn:culmination
c. The highest point of a stratum, as a coalbed. Standard, 2
d. The top of an anticlinal fold of strata.
e. In U.S. mining law, used to designate the highest limit of a vein.
Ballard
f. The top of an inclined haulage plane. See also:brow; landing.
Nelson
g. Point in the center of the face of a concave, noncoring bit.
Long
h. In a classifier or hydrocyclone, the underflow aperture through which
the coarser and heavier fraction of the solids in a pulp is discharged in
accordance with its minimum cross section. Pryor, 3
a. This law gives the owner of a properly located claim on a vein the
right to an indefinite extension on the dip of the vein beyond the
vertical planes through the side lines of the claim. In order to secure
this right, the owner must lay out the end lines of the claim parallel and
of substantial length. A triangular claim would have no apex right and
cannot be patented. Lewis
b. Obsolescent mining law allowing the owner of a lode to follow it in
depth, regardless of the vertical extension of the legal surface
boundaries. Pryor, 3
c. In U.S. mining law, the individual whose claim contains the apex of a
vein may follow and exploit the vein indefinitely along its dip, even if
it passes downdip under adjoining surface property lines.
Syn:law of extralateral rights
See:clinoclase
Any fine-grained igneous rock whose components are not distinguishable
with the unaided eye; a rock having aphanitic texture. CF:aphanitic
Syn:cryptomere; felsite; felsitoid. AGI
a. Said of the texture of an igneous rock in which the crystalline
components are not distinguishable by the unaided eye; also said of a rock
or a groundmass exhibiting such texture. CF:aphanite; phaneritic.
Syn:fine-grained
b. A crystalline texture with individual crystals too small to be visible
to the unaided eye. Syn:cryptocrystalline
A porphyritic igneous rock having a groundmass which the unaided eye
cannot distniguish as either crystalline or noncrystalline. CIPW
A steel-gray argentiferous variety of tetrahedrite. Standard, 2