Roving and enterprising freelance miners and prospectors. Hoover
Milky quartz containing small inclusions of gold; may be cut and polished
for jewelry. Syn:gold matrix
Gold-bearing ore from which the sulfides have been removed by the leaching
of ground waters so that the ore consists almost entirely of quartz
gangue, some iron oxides, and free gold. Newton, 1
A misnomer for lapis lazuli containing flecks of pyrite. Not to be
confused with golden sapphire.
See:stephanite
See:sylvanite
a. The thermite process of welding. Fay
b. The removal of tin from scrap tinplate by dry chlorine. Hess
a. Aventurine spangled close and fine with particles of gold-colored
material. CF:aventurine
b. A translucent reddish-brown glass containing a multitude of tiny
tetrahedra or thin hexagonal platelets of metallic copper that exhibit
bright reflections, producing a popular but poor imitation of aventurine.
Syn:aventurine glass; fire agate. CF:sunstone
a. Minerals containing tellurium forming tellurides of gold and silver;
e.g., sylvanite, calaverite, and petzite.
Statistical Research Bureau
b. One of several natural tellurides of gold and silver, e.g., sylvanite,
(Au,Ag)2 Te4 ; calaverite, AuTe2 ; and petzite, Ag
3 AuTe2 .
a. A misnomer for heat-treated citrine.
b. A misnomer for naturally colored citrine. Syn:false topaz;
topaz-quartz.
A portal type of crane having a lifting capacity of 50 st (45 t) or more,
with the crab traveling along the horizontal beam.
See also:portal crane
A specialized method of surveying a borehole, utilized when a magnetic
compass cannot be used because of local magnetism. The instrument used is
essentially a rigid tube, up to 30 ft (9.2 m) long, which is lowered into
a borehole. The tube fits the borehole closely and contains a fine wire
under tension. The difference between the arc of the tube, when bent at a
crook in the borehole, and the chord of the wire is indicated by a stylus
marking, which can be measured. The dip is read by etch tubes, and a
directional orientation taken at the surface is carried down the hole by
precise alignment of the tube and rods as they are lowered into the
borehole. Long
A railroad car with no top, flat bottom, fixed sides, and sometimes
demountable ends that is used chiefly for hauling heavy bulk materials.
CF:high side
Type of open freight truck used in the United States for mineral
transport. Pryor, 3
A borehole that has deviated from the intended course. Long
a. In crystallography, an instrument for measuring angles between crystal
faces. Types are contact, two-circle, and reflection.
See also:contact goniometer
b. The part of an X-ray diffractometer that rotates the sample and
detector through the Bragg angles of diffraction.
c. A specimen holder with three rotation axes for orientation of single
crystals relative to the X-ray beam in Laue and Wiessberg photography.
Syn:three-circle goniometer
universal stage.
An orthorhombic mineral, Na2 CaAl4 Si6 O20 .7H
2 O ; zeolite group; forms white, finely fibrous, radiating
spherules in cavities in basalt, and as an alteration of nepheline.
A possibly orthorhombic mineral, (Mn,Mg)5 Fe(Si3 Fe)O (sub
10) (OH)8 ; chlorite group; pseudohexagonal with basal cleavage;
soft; with barite, berzeliite, and garnet in small hydrothermal veinlets
cutting skarn at Laangban, Sweden.
Under Metal Exchange rulings, description of metal delivered at an agreed
purity or of a defined quality. Pryor, 3
The green-amphibole or green-pyroxene matrix rock in which rubies are
embedded; Australia and New Zealand.