A trigonal mineral, CaMg2 Cl6 .12H2 O . Also spelled
tachydrite or tachhydrite.
A surveying instrument designed for use in the rapid determination from a
single observation of the distance, direction, and elevation difference of
a distant object; esp. a transit or theodolite with stadia hairs, or an
instrument in which the base line for distance measurements is an integral
part of the instrument. Syn:multiplying constant; tacheometer.
AGI
A method of rapid surveying using the tachymeter; e.g., the stadia method
of surveying used in United States. AGI
a. A small pillar of coal. Fay
b. Veinstone; gangue, etc. See also:taking
Having a rough, catchy surface. Gordon
An assemblage of ropes or wire cables and pulleys arranged for hoisting or
pulling. Long
An electrolytic method for the production of iron powder. Osborne
a. A local term used in the Lake Superior iron-bearing district of
Minnesota for any bedded ferruginous chert or variously tinted jaspery
rock, esp. one that enclosed the Mesabi iron ores (granular hematite); an
unleached iron formation containing magnetite, hematite, siderite, and
hydrous iron silicates (greenalite, minnesotaite, and stilpnomelane). The
term is specif. applied to this rock when the iron content, either banded
or disseminated, is at least 25%. Also spelled taconyte. AGI
b. Since World War II, a low-grade iron formation suitable for
concentration of magnetite and hematite by fine grinding and magnetic
treatment, from which pellets containing 62% to 65% iron can be produced.
AGI
A type of highly abrasive iron ore now extensively mined in the United
States. Sandstrom
See:taconite
A rock of complex mineralogical composition, formed by contact
metamorphism and metasomatism of carbonate rocks. It is typically
coarse-grained and rich in garnet, iron-rich pyroxene, epidote,
wollastonite, and scapolite. Approximate syn: skarn.
See also:calc-silicate hornfels
A monoclinic mineral, KLiMg2 Si4 O10 F2 ; mica
group; at Narsarsuk, Greenland, and Magnet Cove, AR. Also spelled
tainiolite.
An isometric mineral, (Fe,Ni) ; contains 27% to 65% nickel; occurs in iron
meteorites as lamellae or strips flanking bands of kamacite. Also called
gamma-nickel-iron (face-centered cubic). See also:nickel iron
A numbered piece that a miner attaches to or places on each car a miner
loads. The tag is removed at the tipple where the car is credited to the
miner. See also:tally; ticket. CF:wedge rock
See:tracer
a. A graphical method of determining the resistivity of the ground.
AGI
b. A method of interpretation of resistivity sounding data obtained with a
Wenner array over a two-layered Earth. AGI
See:pseudomalachite
A line from a crane boom to a clamshell bucket that holds the bucket from
spinning out of position. Nichols, 1
a. (also plural). The inferior, less valuable, or refuse part of anything;
foots, bottoms, dregs; sediment. See also:tailings
b. The poor grade of ore slime at the lower end of the slime box as it
flows from the stamps. Standard, 2
c. The unexposed end of a brick or stone in a wall; a tailing.
Standard, 2
d. The rear of a shovel deck. Nichols, 1
e. The anchor end of a cable excavator. Nichols, 1
f. A bar or barrier formed behind a small isle or a skerry. Also called
trailing spit; banner bank. Schieferdecker
The anchor for a track cable, or the turn point for a backhaul line in a
cable excavator. Nichols, 2
A joist or beam that abuts against the header joist. Syn:tail joist
Crispin