Under this system the state or the private owner has the right to grant
concessions or leases to mine operators at discretion and subject to
certain general restrictions. It had its origin in the ancient regalian
doctrine that all mineral wealth was the prerogative of the crown or the
feudatory lord and applies in almost every mining country in the world,
except the United States. Syn:concession
See also:take
A bowl-shaped body of limonite or goethite growing in an inverted position
on mineralized bedrock and resembling the shell of an oyster or clam
coated with a rusty deposit. It is roughly oval or circular in plan, with
a smooth or irregular and scalloped outline; it ranges from 2.5 cm to 1 m
in diameter and from 2 to 7.5 cm in height. AGI
Said of a type of mineral or rock fracture that gives a smoothly curved
surface. It is a characteristic habit of quartz and of obsidian. Etymol:
like the curve of a conch (seashell). AGI
A fracture with smooth, curved surfaces, typically slightly concave,
showing concentric undulations resembling the lines of growth of a shell.
It is well displayed in quartz, obsidian, and flint, and to a lesser
extent in anthracite.
a. Said of intrusive igneous bodies, the contacts of which are parallel to
the bedding or foliation of the country rock. CF:discordant
Billings
b. Structurally conformable; said of strata displaying parallelism of
bedding or structure. The term may be used where a hiatus cannot be
recognized, but cannot be dismissed. AGI
c. Said of radiometric ages, determined by more than one method, that are
in agreement within the analytical precision for the determining methods;
or of radiometric ages given by coexisting minerals, determined by the
same method, that are in agreement. AGI
An intimate mixture of an aggregate, water, and portland cement, which
will harden to a rocklike mass.
A shaft-sinking method sometimes used through soft ground down to bedrock.
It is similar to caisson sinking, except that reinforced concrete rings
are used and an airtight working chamber is not adopted. Nelson
A thick layer of reinforced concrete placed in the bottom of a shaft after
it has been sunk to the desired depth and permanently lined. The plug
resists floor lifting and provides a clean, smooth sump. Nelson
See:permanent shaft support; shaft wall.
Machine that helps the aggregate to consolidate with minimum interstitial
porosity. Gives greater strength as less water is incorporated in the mix,
and as consolidation is better than with punning. Pryor, 3
a. A hard, compact mass or aggregate of mineral matter, normally
subspherical, but commonly oblate, disk-shaped, or irregular with odd or
fantastic outlines; formed by precipitation from aqueous solution about a
nucleus or center, such as a leaf, shell, bone, or fossil, in the pores of
a sedimentary or fragmental volcanic rock, and usually of a composition
widely different from that of the rock in which it is found and from which
it is rather sharply separated. It represents a concentration of some
minor constituent of the enclosing rock or of cementing material, such as
silica (chert), calcite, dolomite, iron oxide, pyrite, or gypsum, and it
ranges in size from a small pelletlike object to a great spheroidal body
as much as 3 m in diameter. Most concretions were formed during
diagenesis, and many (esp. in limestone and shale) shortly after sediment
deposition. CF:nodule
b. A collective term applied loosely to various primary and secondary
mineral segregations of diverse origin, including irregular nodules,
spherulites, crystalline aggregates, geodes, septaria, and related bodies.
Not recommended usage. AGI
Characterized by, consisting of, or producing concretions; e.g., a
concretionary ironstone composed of iron carbonate with clay and calcite,
or a zonal concretionary texture (of an ore) characterized by concentric
shells of slightly varying properties due to variation during growth.
AGI
Minerals, usually monomineralic aggregates, which are found in detached
masses, the forms being sometimes spherical, sometimes irregular, e.g.,
flint. Nelson
Shock or sharp airwaves caused by an explosion or heavy blow.
Nichols, 1
An inclined table, which is agitated by a series of shocks, while
operating like a buddle. It may be made self-discharging and continuous by
substituting for the table an endless rubber cloth, which is slowly moving
against the current of water, as in the Frue vanner. Also called a
percussion table. Fay
The process by which a vapor becomes a liquid or solid; the opposite of
evaporation. AGI
a. An apparatus used for condensing vapors obtained during distillation;
it consists of a condenser tube, either freely exposed to air or contained
in a jacket in which water circulates. CTD
b. An accumulator of electrical energy. Also called capacitor.
Crispin
condenser-discharge blasting machine
A blasting machine that uses batteries or magnets to energize one or more
condensers (capacitors) whose stored energy is released into a blasting
circuit, to initiate detonators. Dick, 2
In ore dressing, smelting, and refining, one who operates an automatic
machine in which fireclay condensers are made. DOT