A logarithmic grade scale devised by Johan A. Udden (1859-1932), U.S.
geologist; it uses 1 mm as the reference point and progresses by the fixed
ratio of 1:2 in the direction of decreasing size and of 2:1 in the
direction of increasing size, such as 0.25, 0.5, 1, 2, 4.
See also:Wentworth grade scale
The group of calcium garnets uvarovite, grossular, andradite, goldmanite,
hibschite, kimzeyite, and schorlomite
An isometric mineral, (Ca,Ti,Al,Zr)2 O3 ; forms black
octahedra in a nepheline syenite near Lake Magad, Tanzania.
A discredited term equal to thomsonite. Am. Mineral., 1
A variety of natural asphalt occurring in the Uinta Valley, Utah, as
rounded masses of brilliant black solid hydrocarbon. Syn:gilsonite;
mineral rubber. CMD
A triclinic mineral, NaCaB5 O6 (OH)6 .5H2 O ;
soft; forms silky white, saline crusts and masses of extremely fine
acicular crystals; in saline lake deposits as in Nevada and Chile. Also
called cotton ball; boronatrocalcite; natronborocalcite; natroborocalcite.
A triclinic mineral, NiSbS ; cobaltite group; pseudocubic; metallic;
steel-gray to silver-white; in veins; a source of nickel. Also called
nickel-antimony glance.
These machines have powerful electromagnets in a wedge section. The
material is treated on rolls on which magnetism is induced; they consist
of alternate disks of soft iron and some nonmagnetic material. The ore is
fed over the first roll, which removes the most magnetic material, and the
tailings go on to the second, which is weaker, where a second separation
is made. Liddell
A kind of euvitrain that consists completely of ulmin but that is not
precipitated from solution. CF:collain
The process of peat formation. Tomkeieff
See:Vandyke brown
a. A maceral of brown coal within the huminite group, consisting of
gelified plant-cell walls (ICCP, 1971). AGI
b. A variety of euvitrinite characteristic of ulmain and consisting of
gelified but not precipitated plant material. CF:collinite
A hypabyssal rock composed essentially of large phenocrysts of alkalic
feldspar, sodic pyroxene, amphibole, and nepheline with smaller
phenocrysts of accessory olivine. Feldspar, pyroxene, and amphibole recur
in the groundmass. A porphyritic variety of olivine-bearing phonolite.
Syn:uraninite
a. The determination of the elements contained in a compound, as
distinguished from proximate analysis, which is the determination of the
compounds contained in a mixture. Standard, 2
b. In the case of coal and coke, the determination of carbon and hydrogen
in the material, as found in the gaseous products of its complete
combustion, the determinations of sulfur, nitrogen, and ash in the
material as a whole, and the calculation of oxygen by difference.
ASTM
c. The principal reason for the ultimate analysis of coal is for the
classification of coals according to rank, although it is often used for
commercial and industrial purposes when it is most desirable to know the
sulfur content of coal. Also known as total analysis of coal.
Cooper
The average load per unit of area required to produce failure by rupture
of a supporting soil mass. See also:bearing capacity
The pressure under which a foundation will settle with no increase of
load. See also:plate bearing test
The percent of carbon dioxide that would appear in the flue gases if
combustion were perfect. Varies with the fuel. Strock, 2
That point at which failure by crushing occurs. Pryor, 3
The percentage of permanent deformation remaining after tensile rupture,
measured over an arbitrary length including the section of rupture.
Roark
ultimately controlled variable
In mineral processing, the variable whose control is the end purpose of
the automatic control system. Fuerstenau
The ultimate strength of a material in tension, compression, or shear,
respectively, is the maximum tensile, compressive, or shear stress that
the material can sustain, calculated on the basis of the ultimate load and
the original or unstrained dimensions. It is implied that the condition of
stress represents uniaxial tension, uniaxial compression, or pure shear,
as the case may be. Roark