In ore microscopy, a replacement pattern in which the younger mineral
forms a series of scallop-shaped incursions into the host mineral, which
resemble filled dental cavities. AGI
In geology, an isoclinal fold. See also:isocline
A metallurgical method for treating lead ore, the characteristics of which
are the smallness of the charge; the slow roasting, so that for every part
of lead sulfide one part of sulfate and at least two parts of oxide are
formed; the low temperature at which all of the operations are carried on;
and the aim to extract all the lead in the reverberatory. The hearth is
inclined toward the flue, and the lead is collected outside the furnace.
Syn:Corinthian process
See:loader; chute loader; boxcar loader; loading conveyor.
A twinned crystal in which the twinning axis is the c axis, the operation
is a rotation of 180 degrees , and the contact surface is parallel to the
side pinacoid; common in the alkali feldspars. Also spelled Karlsbad twin.
AGI
A worker who handles mine or railroad cars at a mine. May be designated
according to job, such as brakeman; car cleaner; car pincher; car runner;
pusher. Also called car handler. DOT
See:blast roasting
A carmine to tile-red lead-iron-arsenate, perhaps Pb3 As2 O
8 .10FeAsO4 . Found in clusters of fine needles; also in
spheroidal forms. Fay
See:cairn
An orthorhombic mineral, KMgCl3 .6H2 O ; milk-white to
reddish; a saline residue.
In ore dressing, smelting, and refining, one who makes carnallite flux
used in magnesium refining--by weighing carnallite ingredients according
to formula and mixing them thoroughly, using a shovel. The mixture is then
melted in a furnace crucible and poured into cooling pans. DOT
A triclinic and isometric compound, NaAlSiO4 ; a high-temperature
polymorph of nepheline.
A translucent pale to deep- or orange-red variety of chalcedony containing
iron impurities. CF:sard
See:carnelian
See:car runner
A monoclinic mineral 2[K2 (UO2 )2 (VO4 ) (sub
2) .3H2 O] ; bright yellow to lemon- and greenish-yellow; strongly
radioactive; commonly occurs mixed with tyuyamunite; widespread in
Colorado, Utah, New Mexico, and Arizona; occurs chiefly in crossbedded
sandstones of Triassic or Jurassic age, either disseminated or as
relatively pure masses around petrified or carbonized vegetal matter.
Secondary in origin, having been formed from the action of meteoritic
waters on preexisting uranium minerals; a source of uranium and radium.
Syn:yellow ore
An orthorhombic mineral, MnAl2 Si2 O6 (OH)4 ;
in yellow laths elongated in the c direction with prismatic cleavage at
68.5 degrees .
In anthracite, bituminous, and metal mining, a laborer who moves railroad
cars into position directly under loading chutes at a breaker or tipple,
inserting a pinch bar under the car wheels and bearing down or pulling up
on it to force the car forward. Also called car shifter; car spotter;
railroad-car shifter; spotter. DOT
Eng. See:capel
Any of the marbles quarried near Carrara, Italy. The prevailing colors are
white to bluish, or white with blue veins; a fine grade of statuary marble
is included.
a. An appliance for reducing or controlling the speed of mine cars.
Nelson
b. A car retarder consists of a brakeshoe located along the track. On an
electrical impulse, it is forced against both sides of the car wheels by
compressed air. Control can be manual or automatic. Used to control the
speed of railroad cars in industrial yards. Best, 1