An isometric mineral, (U,Ca,Ce)2 (Nb,Ta)2 O6 (OH,F) ;
pyrochlore group; radioactive; yellow-brown; with samarskite in pegmatites
in Mitchell County, NC, and at Hybla, ON, Canada. Formerly called
hatchettolite. CF:betafite
A mixture of trona and thermonatrite. See also:sodium sesquicarbonate
A tetragonal mineral, CO(NH2 )2 . Carbonyl diamide; also
called carbamide.
The treatment of quicksilver ores by heating in iron retorts with
admixture of lime. Fay
A division of the European Lower Cretaceous characteristically developed
in certain parts of France and Belgium. Standard, 2
Eng. Kentish term for ragstone. Also spelled urnell or ournal.
A pathogenic precipitate occurring in humans and other animals. They are
very complex and include numerous biominerals, chiefly phosphates and
oxalates. Syn:kidney stone
A light-colored member of the ijolite series that is composed chiefly of
nepheline and 0% to 30% mafic minerals, esp. acmite and apatite.
CF:melteigite
(now Lovozero), Kola Peninsula, Russia. AGI
a. A deep violet, very transparent amethyst.
b. Any amethyst originating along the border between Uruguay and Brazil.
A resettable salvage diamond. See also:usable stone; usables.
Long
The product of a mine, or of a beneficiating or agglomerating plant, which
is shipped without further processing to the consumer. USBM, 7
Salvaged diamonds considered as being fit for resetting and reuse in
another bit or tool. See also:usable diamond
See:usable diamond
A diamond bit so dulled by use that it is no longer of any value as a
cutting tool. Long
Working area of a screen. The nominal area, less any area occupied by
fixings or supports that obstruct the passage of material over or through
the screen deck. BS, 5
For a mine fan, the natural ventilation pressure deducted from the total
ventilation pressure required to circulate air through the mine.
Roberts, 1
An articulated yielding arch, provided by a single bolted joint at the
crown. The joint is so designed that the bolt is not subjected to shear
stress. The yield element is a rectangular box in which the foot of the
arch rests. The resistance to yield is by means of a piece of crushing
timber placed in the box from the bottom before setting.
See also:steel arch; steel support; Toussaint-Heintzmann arch.
Nelson
See:universal stage
A mineral, Pb(Bi,Sb)6 S10 ; forms gray prismatic crystals in
bismuth ore at the Ustarasaisk deposit in western Tyan-shan, Siberia.
By this term in a deed, the grantee has and may enjoy the right to go upon
the land and explore for, open, and operate mines, take out and sell the
products, and do all things incident to that work. Ricketts
A discredited term for jarosite or natrojarosite.
See also:natrojarosite