A form of wad; a soft, earthy manganese dioxide, containing up to about
32% cobalt oxide. Sometimes referred to as earthy cobalt. Syn:asbolite;
cobalt ocher. See also:asbolan
See:asbolan; asbolane.
A mine ventilation system in which the fresh intake air flows down to the
bottom end of the workings and then ascends along the faces to the main
return. See also:descensional ventilation; antitropal ventilation;
homotropal ventilation.
A theory of hypogene mineral-deposit formation involving mineralizing
solutions rising through fissures from magmatic sources in the Earth's
interior. CF:descension theory
See:szaibelyite
An igneous rock with the same chemical composition as its parent magma,
i.e., undifferentiated. CF:diaschistic
Said of the rock of a minor intrusion that has a composition equivalent to
that of the parent magma, i.e., in which there has been no significant
differentiation. CF:diaschistic
a. The inorganic residue after burning, esp. of coal. Ignition generally
alters both the weight and the composition of the inorganic matter.
See also:ash yield; extraneous ash; inherent ash. AGI
b. Fine pyroclastic material (under 2.0-mm diameter; under 0.063-mm
diameter for fine ash). The term usually refers to the unconsolidated
material but sometimes is also used for its consolidated counterpart,
tuff. Syn:dust; volcanic ash; volcanic dust; pumicite. AGI
c. Inorganic residue remaining after ignition of combustible substances,
determined by definite prescribed methods. ASTM
A tetragonal mineral, K5 Na5 (Y,Ca)12 Si28 O
70 (OH)2 (CO3 )8 .3H2 O ; occurs in
small pink needles at Narsarsuk, Greenland.
A graph that shows a relation between the specific gravity of fractions of
a coal sample floated in liquids of step-by-step increased density, and
the percentage of ash in each such fraction. Syn:tromp curve
Pryor, 3
Early name applied to tourmaline because of its polar electrostatic
property.
The difference between the percentage ash of a product of a separation and
that shown by the washability curve (based on the reconstituted feed) of a
product with the same properties (usually percentage of ash).
BS, 5
A measure, in terms of temperature, of fusion of coal ash prepared and
tested under standard conditions. BS, 4
The temperature at which a special test cone made from particles of ash
obtained from the coal will (1) begin to deform, i.e., soften, or (2)
completely deform or fuse into a blob. Nelson
Rectangular pieces of stone of nonuniform size that are set randomly in a
wall. AGI
The curve obtained from the float-and-sink analysis by plotting the ash
contents of successive fractions against specific gravity. BS, 5
An indurated deposit of fine volcanic ash. AGI
The percentage of material remaining after a fuel is burned; that portion
of a laboratory sample remaining after heating under standard conditions
to constant weight; i.e., until all the combustible matter has been burned
away. See also:ash; extraneous ash; inherent ash. Nelson
See:asparagus stone
A yellow-green variety of apatite. Syn:asparagolite
a. The gross or overall lithologic or biologic characteristics of a
stratigraphic unit as expressed at any particular point. AGI
b. The angle made by a target with the line joining it to the observation
point is known as the aspect of the target. Hunt