A British spelling of feldspar following an error by Kirwan. Hess
An obsolete synonym of felsite. AGI
See:felty
Said of the texture of dense, holocrystalline igneous rocks consisting of
tightly appressed microlites, generally of feldspar, interwoven in
irregular, unoriented fashion. CF:trachytic
felted.
Said of an igneous rock having one or more normative, dark-colored iron-,
magnesium-, or calcium-rich minerals as the major components of the norm;
also, said of such minerals. Etymol. a mnemonic term derived from ferric +
magnesium + ic. CF:basic; salic; mafic; felsic. AGI
Fragile, weak, or slender as in the case of a thin, soft roof bed over a
coal seam. Nelson
Three or more geologic sections showing the relationship of wells to
subsurface formations. The scales diminish with distance from the
foreground to give proper perspective. When several sections are used
together, they form a fencelike enclosure, hence the name. Similar in some
respect to a block diagram, but it has the advantage of transparency,
which is not possible in a block diagram. AGI
A thin pillar of coal, adjacent to the gob, left for protection while
driving a lift through the main pillar.
A quartzo-feldspathic rock that has been altered by alkali metasomatism at
the contact of a carbonatite intrusive complex. The process is called
fenitization. Fenite is mostly alkalic feldspar, with some aegirine,
subordinate alkali-hornblende, and accessory sphene and apatite.
AGI
See:window
A monoclinic mineral, FeWO4 ; wolframite series with manganese
replacing iron toward huebernite; weakly ferrimagnetic; sp gr, 7.5; in
quartz veins; an ore of tungsten. Syn:eisinwolframite
A very rare, strongly radioactive, possibly orthorhombic, sulfur-yellow
translucent mineral, U3 (VO4 )2 .6H2 O ; found
associated with other uranium minerals. Ferganite may be a leached or
weathered product of tyuyamunite. A source of vanadium.
Crosby; Osborne
See:ferganite
Monoclinic (beta) and orthorhombic minerals (Ce,Nd,La,Y)NbO4 ,
further speciated according to the predominant rare-earth element; dull to
vitreous brownish black; in pegmatites associated with euxenite, monazite,
gadolinite, and other rare-earth minerals in North Carolina, South
Carolina, Virginia, Texas, Norway, Sweden, and Africa.
The process of decomposition of carbohydrates with the evolution of carbon
dioxide or the formation of acid, or both. Tomkeieff
A hexagonal mineral, (Ca,Sr)5 (AsO4 ,PO4 )3
(OH) ; apatite group; in veinlets in manganese ore at Sitipar, Chindwara
district, India.
a. A vanadium ore. Osborne
b. A monoclinic mineral, Ca3 V40 O100 .50H2 O;
dull-green, cryptocrystalline to fibrous masses in the oxidized zone of
the abandoned Minasragra vanadium deposit near Cerro de Pasco, Peru.
A screening machine, utilizing inclined supports, developed in southern
Europe for screening small sizes of ore and sand. The wooden screen frame
is set horizontally and supported on flexible wooden staves inclined at
about 65 degrees from the horizontal. The connecting rod also is inclined
to the screen frame, so as to be approx. at right angles to the supports.
Mitchell
Supporting batten used originally as a slanting support under a shaking
screen. When the screen was pushed forward the radial motion of the truss
caused it to rise slightly, giving a throwing motion to the load and
aiding the gravity-assisted return as the reciprocating action of the
screen vibrator was reversed. The principle is used in shaking tables such
as the James. Pryor, 3
Any of various classes of compounds containing iron and oxygen in the
anion. Webster 3rd
The statement that the centrifugal force produced by the rotation of the
Earth (Coriolis force) causes a rotational deflection of currents of water
and air to the right in the Northern Hemisphere and to the left in the
Southern Hemisphere. AGI