Incorrect name for alexandritelike sapphire; also for so-called synthetic
alexandrite.
The property of some chrysoberyl and other minerals and stones to appear
green in sunlight, but red under incandescent illumination.
See:chameleonite
A waxlike resin from Kaluga, Russ, which resembles compact turf. Also
spelled alexjejevite.
Photosynthetic, almost exclusively aquatic, plants of a large and diverse
division (Algae) of the thallophytes, including seaweeds and their
fresh-water allies. It ranges in size from simple unicellular forms to
giant kelps several meters long, and displays extremely varied life-cycles
and physiological processes, with, e.g., different complexes of
photosynthetic pigments. Algae range from the Precambrian. An individual
plant is called an alga. AGI
Of, pertaining to, or composed of algae. AGI
Coal composed mainly of algal remains, such as Pila, Reinschia, etc. Also
called boghead coal. Tomkeieff; AGI
A limestone composed largely of the remains of calcium-carbonate-producing
algae, or one in which such algae bind together the fragments of other
calcium-carbonate-producing forms. AGI
An organic reef in which algae are or were the principal organisms
producing calcium carbonate, e.g., off the coast of Bermuda. The reefs may
be up to 10 m high and more than 15 m across. AGI
See:stromatolite
A general term for a bitumen derived from algae. Tomkeieff
Equivalent to peat of the humic coal series. AGI
Designates the characteristic maceral of boghead coal. In reflected light
it is very difficult to recognize the cellular structure of the algae. The
reflecting power of the maceral is much weaker than that of vitrinite and
is also weaker than that of sporinite in coals of low rank. In transmitted
light, alginite sometimes shows structure (of colonies of algae). The
color is yellow to orange. Alginite is best recognized by luminescent
microscopy; it shows marked luminescence of varying color--silvery blue,
green, yellowish brown. The humic constituents either are not luminescent
or show a different kind of luminescence to the alginite. Syn:algite
IHCP
The constituent petrological unit, or maceral, of algal material present
in considerable quantity in algal or boghead coal. See also:alginate
AGI
a. Arsenide of copper occurring as a white incrustation in the Algodona
silver mine, Chile. CTD
b. An orthorhombic mineral, Cu6 As ; pseudohexagonal.
Orogeny and accompanying granitic emplacement that affected Precambrian
rocks of northern Minnesota and adjacent Ontario about 2.4 billon years
ago; it is synonymous with the Kenoran orogeny of the Canadian
classification. AGI
a. In mine surveying, a movable arm used to read horizontal angular
distances. Pryor, 3
b. A device having a level bubble combined with a quarter or a half circle
graduated in degrees that is used by drillers to determine the inclination
of a drill stem and/or borehole at the collar of the borehole. Also called
angle level; angle rule; clinometer; clinometer rule. Long
c. An instrument used in planetable surveying, consisting of a telescope
or sighting device pivoted to swing through a vertical graduated arc atop
a vertical stand attached to a steel rule, one edge of which is parallel
with the sight line of the telescope. Long
d. Sometimes incorrectly used as a syn. for transit; theodolite.
Long
e. A rule equipped with simple or telescopic sights, used for determining
the directions of objects, specif., a part of a surveying instrument
consisting of a telescope or other sighting device, with index and reading
or recording accessories. AGI
f. A surveying instrument used with a planetable for mapping; e.g.,
peep-sight alidade and telescopic alidade. AGI
Filling material brought from the surface or from some place other than
the mine. Stoces
a. To position a drill so that its drill stem is centered on a point and
parallel to a predetermined angle and compass direction. Also called line
in; lineup. Long
b. To reposition a drill and bring its drill stem over the center and
parallel with a newly collared drill hole. Long
a. The planned direction of a tunnel or other roadway driven irrespective
of coal seam or orebody structure; the planned direction of longwall
panels or face lines. Nelson
b. Formation or position in line, or, more properly, in a common vertical
plane. Seelye, 2
c. The laying out of the axis of a tunnel by instrumental work.
Stauffer
d. See:coplaning
e. In railway or highway surveying, the ground plan, showing the alignment
or direction of the route to be followed, as distinguished from a profile,
which shows the vertical element. Seelye, 2
f. The act of laying out or regulating by line; adjusting to a line.