The general term for alloys of aluminum and magnesium used for structural
purposes. Hammond
Includes loosening up of shallow or small outcrops of rock and breaking
boulders. It may constitute the entire job, be done in connection with
dirt excavation, or follow heavy blasting that has failed to cut
gradelines or slope lines, or has left chunks too large to load.
Nichols, 1
See:burden
See:leucocratic
A peculiar brightening of molten silver, indicating that maximum purity
has been attained. Occurs in cupellation. Standard, 2; Fay
See:turbidimeter
The visible geometric figure observed when an etched flat surface of
quartz is placed over a pinhole-focused light source.
Am. Mineral., 2
In metallurgy, annealing. Standard, 2
Person who uses an electric extension light as an aid in detecting
blisters and flaws in the inside of green pipe. DOT
a. A rock-forming mineral of a detrital sedimentary rock, having a
specific gravity lower than a standard (usually 2.85); e.g., quartz,
feldspar, calcite, dolomite, muscovite, feldspathoids.
CF:heavy mineral
b. A light-colored mineral. AGI
Eng. An explosion of combustible gases caused by electric current, during
a thunderstorm, entering a mine and igniting the gas. Fay
A lightning gap is a break about 6 ft (1.8 m) long made at the mine
entrance in blasting circuits, used in firing blasts from the outside, to
prevent lightning discharges from following the circuits into the mine.
A system to enable high electrical discharge from the atmosphere to be
conducted safely to earth by one or more conductors. The provision is very
important in the case of mine explosive stores and also headgears, tower
winders, and chimneys. Nelson
See:fulgurite
A railway built to narrow gage. Hammond
See:proustite
See:proustite
See:proustite
Ordinary water, H2 O , as distinguished from heavy water, D2
O , D being the symbol for deuterium (heavy hydrogen or hydrogen 2).
Lyman
An aggregate with a relatively low specific gravity; e.g., pumice,
volcanic cinders, expanded shale, foamed slag, or expanded perlite or
vermiculite. CF:aggregate
A concrete made with lightweight aggregate. AGI