a. An orthorhombic mineral, CuTe ; with rickardite and native tellurium,
it forms coatings on rocks; occurs at the Good Hope Mine, Vulcan, CO.
b. A dark-colored, hard variety of vulcanized India rubber that differs
from the softer rubber in having been vulcanized at a high temperature;
ebonite. It takes a high polish, and is used for making combs, ornaments,
etc., and in electrical work because of its fine insulating properties.
Standard, 2
A general name for igneous rocks of fine grain size, normally occurring as
lava flows, and thus in direct contrast with plutonites. CTD
A rubber that has been heated with sulfur to change its properties.
Nelson
Consists essentially of two heavy metal plattens that are placed one on
each side of the previously prepared joint and clamped firmly together.
Each platten is heated, and this combined application of heat and pressure
over a period completes the joint. These machines are used to vulcanize
the belt joints of conveyors.
High explosive composed of 30% nitroglycerin, 52.5% sodium nitrate, 10.5%
charcoal, and 7% sulfur. Pryor, 3
A scaly, granular variety of anhydrite; may be admixed with silica; cut
and polished for ornamental purposes.
a. A funnel box; also, having a groove or grooves of a triangular section.
Webster 2nd
b. See:spitzkasten
A tetragonal mineral, (Pd,Ni)S ; isomorphous with braggite; in minute
grains or prisms; at Norilsk, Russia.
A dual-scale, direct-reading instrument for measuring the combustible
gases percentage in mine air. It gives combustible gases readings over the
range from 0.2% to 5% and is graduated 0.1% per division on the scale.
Nelson
Banded cream to black and gray to purple chocolate-colored slate from
Massachusetts. Schaller
a. A dirty sandstone that consists of a mixed variety of angular and
unsorted or poorly sorted mineral and rock fragments, and of an abundant
matrix of clay and fine silt; specif. an impure sandstone containing more
than 10% argillaceous matrix. The term is used for a major category of
sandstone, as distinguished from arenite. AGI
b. A clastic sedimentary rock in which the grains are almost evenly
distributed among the several size grades; e.g., a sandstone consisting of
sediment poured in to a basin of deposition at a comparatively rapid rate
without appreciable selection or reworking by currents after deposition,
or a mixed sediment of sand, silt, and clay in which no component forms
more than 50% of the whole aggregate. AGI
c. A term commonly used as a shortened form of graywacke. This usage is
not recommended. AGI
d. Originally, a term applied to a soft earthy variety of basalt, or to
the grayish-green to brownish-black claylike residue resulting from the
partial chemical decomposition of basalts, basaltic tuffs, and related
igneous rocks. Syn:vake
mining term signifying a large stone or stoniness in general. AGI
Rocklike clay, formed by the decomposition of basalts in situ.
CF:graywacke
a. An earthy, dark brown to black mineral material consisting chiefly of
an impure mixture of manganese oxides and oxyhydroxides with variable
amounts of copper, cobalt, and iron oxides and oxyhydroxides and silica
plus 10% to 20% adsorbed water. It is commonly soft (soiling hands), but
may be hard and compact, and has a low density. Wad results from the
decomposition of other manganese minerals and accumulates in marshy areas
or other zones of ground-water emission where it is an ore of manganese.
See also:asbolan
earthy manganese; manganese hydrate.
b. A general term for massive, fine-grained manganese oxides and
oxyhydroxides of low density, but not further identified.
c. In drilling, a term applied to rock cuttings that tend to ball and
adhere to drill-string equipment and borehole walls in lumps. Long
Eng. A tool for extracting a pebble or broken tool from the bottom of a
borehole. It consists of two spiral steel blades arranged something like a
corkscrew. See also:spiral worm
Paper or cloth placed over explosives in a hole. Nichols, 1
An earlier type of centrifugal fan. It had no external casing, but
delivered directly to the atmosphere all around its periphery. The veins
were curved backwards in the direction of rotation and the air was led
into the fan by a curved inlet passage or throat. It was usually driven by
steam at about 70 rpm; efficiency about 40%; external diameter of about 30
ft (9.1 m). See also:Sirocco fan
A hexagonal mineral, K2 CaZ.(SiO3 )4 ; forms
hexagonal plates; in Western Australia.
See:wad coil; spiral worm.
a. A term used in the desert regions of Southwestern Asia and Northern
Africa for a stream bed or channel, or a steep-sided and bouldery ravine,
gully, or valley, or a dry wash, that is usually dry except during the
rainy season, and that often forms an oasis. AGI
b. The intermittent and torrential stream that flows through a wadi and
ends in a closed basin. AGI
c. A shallow, usually sharply defined, closed basin in which a wadi
terminates.---Etymol: Arabic. Variant plurals: wadis; wadies; wadian;
widan. See also:arroyo; nullah. Also spelled: wady; waddy. Syn:oued;
widiyan. AGI
A process by which low-grade ores, slags, or residues from retorts may be
treated either for the recovery of zinc alone or for the recovery of zinc,
lead, and tin. It employs a rotary kiln, and the zinc-bearing material
mixed with fine coal is fed into the kiln and heated, so that the zinc is
vaporized and converted to oxide fume. Newton, 1
a. A name given to the rough slice obtained by sawing directly from a
mother crystal or section. The process of manufacturing wafers is
variously known as wafering, wafering from the crystal or slab, wafering
from the mother crystal, and baloney slicing. Am. Mineral., 2
b. Small sheet of electroceramic material 0.001 to 0.01 in (0.025 to 0.25
mm) thick for use in electronic equipment, particularly in miniature
capacitors, transistors, resistors, and other circuit components.