See:phaneritic
Porosity visible without the aid of a microscope, such as pipes and
blowholes in ingots. Newton, 1
a. Visible at magnifications of from 1 to 10 diameters. ASM, 1
b. Visible without a microscope or in a hand specimen.
See also:megascopic
a. The general arrangement of crystals in a solid metal (for example, an
ingot) as seen by the naked eye or at low magnification. The term is also
applied to the general distribution of impurities in a mass of metal as
seen by the naked eye after certain methods of etching. CTD
b. The structure of metals as revealed by examination of the etched
surface of a polished specimen at a magnification not exceeding 10
diameters. ASM, 1
c. A structural feature of a rock that is discernible to the unaided eye,
or with the help of a simple magnifier. Fay
d. The arrangement of crystals in a metal or in a rock that, with or
without etching or other chemical treatment, is discernible to the unaided
eye or with the help of a simple magnifier (generally less than 10X).
Applied to the group of contact-metamorphic rocks represented by spotted
slates, to denote its spotted or knotted character. The term may be
applied either to the rock or to its structures.
See also:spotted slate
See:spotted slate
A strongly dichroic variety of blue beryl obtained, as a gemstone
material, from Malagasy Republic. CTD
A method of obtaining pig iron, consisting of charging a retort with a
mixture of iron ore, coal, and enough water to form a paste; and injecting
compressed air at 2 to 4.2 kg/cm2 pressure and at 815 to 930
degrees C to burn the coal. In a few minutes the entire mineral charge is
heated to 980 to 1,095 degrees C, which is the optimum range for hydrogen
reduction; then hydrogen is injected at a temperature of 815 to 923
degrees C at 2 to 8 kg/cm2 pressure so that it penetrates the
entire mass and reacts with the iron oxide to produce steam and metallic
iron. About 50% of the injected hydrogen reacts with the ore to produce
sponge iron. Sulfur is oxidized by the hot air and is eliminated by the
hydrogen. Osborne
a. A recent deposit, as of river silt. Fay
b. Ground formed by filling in natural or artificial pits with hardcore or
rubbish. CTD
Citrine variety of quartz. CF:false topaz; Spanish topaz.
Coupled; the assembled component parts of a drill string or pipe system.
Long
A plot of mean absolute difference of paired sample measurements as a
function of distance and direction. Madograms are not true variograms, and
generally should not be used in kriging. If used, the kriged estimates
might be "reasonable," but the kriging standard deviations will be
meaningless.
A fossiliferous limestone occurring in a variety of colors. It takes a
high polish, is used as a marble, and derives its name from its most
characteristic fossil, a species of coral.
An intrusive trachytic rock, regarded as a differentiation product of a
gabbroic magma. Maenite is a bostonite relatively high in calcium and low
in potassium.
Said of igneous rocks containing roughly equal amounts of felsic and mafic
minerals, color index 40 to 70. AGI
Pertaining to or composed dominantly of the ferromagnesian rock-forming
silicates; said of some igneous rocks and their constituent minerals.
CF:basic; felsic. See also:mafite
See:basic front
Any dark mineral in Johannsen's classification of igneous rocks.
See also:mafic
a. A storage place for explosives. Jones, 1
b. A building specially constructed and located for the storage of
explosives. CF:powder chest
An isometric mineral, gamma-Fe2 O3 ; magnetite series;
spinel group; dimorphous with hematite; strongly ferrimagnetic.
Syn:oxymagnite
Roasted copper pyrites. Pryor, 3