The study and determination of stable phases present under various
conditions of pressure, temperature, and composition according to the
Gibbs phase rule; used in the study of mineral genesis.
CF:crystallogeny
In the Convertol process, replacement of the film of water covering a coal
particle by a film of oil. BS, 5
A device for measuring the difference in phase of two alternating currents
or electromotive forces. Webster 3rd
The statement that for any system in equilibrium, the number of degrees of
freedom is two greater than the difference between the number of
components and the number of phases. It may be symbolically stated as F =
(C-P) + 2. See also:mineralogical phase rule
A device employed to alter the phase of a wave. NCB
Any portion of the universe that can be isolated completely and
arbitrarily from the rest for consideration of the changes that may occur
within it under varied conditions. In a closed system, energy may cross
the system boundary, but matter may not. In an open system, both energy
and matter may enter or leave as required. An equilibrium system is closed
with all phases in their lowest energy states. The variance (degrees of
freedom) of an equilibrium system is its number of components minus its
number of phases plus two. A steady-state system is open with all phases
in their lowest energy states while matter streams through it. Systems may
be described by the number of their components; e.g., unary for one
component, binary for two, ternary for three, etc. They are commonly
defined in terms of their components; e.g., the system CaO-MgO-SiO2
-H2 O is a quaternary system.
The inversion of one crystalline assemblage of components from one
symmetry to another; e.g., calcite to aragonite.
See:phenakite
A trigonal mineral, Be2 SiO4 ; colorless to yellow, red, or
brown; a minor gemstone sparsely found in granite pegmatites. It is
sometimes confused with quartz. Not to be confused with fenaksite.
Syn:phenacite
a. A variety of muscovite having high silica.
b. A transparent or translucent stone (probably crystalline gypsum) used
by the ancients for windows.
a. Applied to certain conditions under which coal was formed, namely those
of open waters into which the plant debris was swept from the adjoining
land. Tomkeieff
b. Refers to vegetable matter deposited under water in contrast to that
laid down on a wet substratum. CF:crypthydrous
A term for large crystals or mineral grains floating in the matrix or
groundmass of a porphyry. Syn:inset
See:phaneritic
A soluble, crystalline acidic compound; C6 H5 OH ; has a
characteristic odor. It is present in coal tar and in wood tar. It is a
powerful caustic poison and in a dilute solution, a useful disinfectant.
Used chiefly in making resins and plastics, dyes, and pharmaceuticals
(such as aspirin). Syn:benzenol; hydroxybenzene; carbolic acid.
Handbook of Chemistry and Physics, 2
A logarithmic transformation of the Wentworth grade scale in which the
negative logarithm to the base 2 of the particle diameter (in millimeters)
is substituted for the diameter value (Krumbein, 1934); it has integers
for the class limits, increasing from -5 for 32 mm to +10 for 1/1,024 mm.
The scale was developed specif. as a statistical device to permit the
direct application of conventional statistical practices to sedimentary
data. See also:Wentworth grade scale
A leveling rod in which the hundredths of feet, or eighths of inches, are
marked by alternate bars of color the width of the measurement.
Nichols, 1
A compact, blue, hydrated copper and iron sulfate, Fe2 Cu(SO (sub
4) )4 .12H2 O , produced by decomposition of chalcopyrite.
Standard, 2
A monoclinic mineral, (K,Na,Ca)1-2 (Si,Al)8 O16 .6H
2 O ; zeolite group; commonly occurs in complex twinned crystals; in
basalt amydules, in pelagic red clays, in palagonite tuffs, in alkaline
saline lakes from silicic vitric volcanic ash, in alkaline soils, and
around hot springs in Roman baths.
Designed to obtain cores up to about 4 ft (1.2 m) in length, the Phleger
corer is utilized where only the upper layers of the sea bottom are to be
analyzed. Hunt
In coal, the outer conducting part of the central cylinder or vascular
tissues. It consists primarily of sieve tubes and companion cells, phloem
fibers or bark fibers, stone cells, and parenchymatous cells. Hess
A monoclinic mineral, K2 Mg6 (Si6 Al2 O (sub
20) )(F,OH)4 ; a magnesium-rich end-member of the biotite crystal
solution series; mica group; pseudohexagonal with perfect basal cleavage;
occurs in crystalline limestones as a product of dedolomitization, in
potassium-rich ultramafic rocks, as an alteration mineral in sulfur-rich
hydrothermal assemblages, and in kimberlites. Syn:magnesium mica;
amber mica; brown mica.