A black variety of andradite garnet. Syn:melanite
An actinometer that measures the intensity of direct solar radiation.
AGI
The pyroxene group plus amphibole group. See also:pyroxene
A general name for a fossil combustible substance. Tomkeieff
a. An isometric mineral, FeS2 ; dimorphous with marcasite; forms a
series with cattierite; crystallizes in cubes and pyritohedra; sparks
readily if struck by steel; metallic; pale bronze to brass yellow;
hardness varies from 6.0 to 6.5; occurs in veins, as magmatic segregation,
as accessory in igneous rocks, and in metamorphic rocks, in sedimentary
rocks including coal seams; a source of sulfur; may have included gold.
Syn:Alpine diamond; iron pyrite; fool's gold; mundic; common pyrite.
b. The mineral group aurostibite, bravoite, cattierite, erlichmanite,
fukuchilite, geversite, hauerite, insizwaite, krutaite, laurite, malanite,
maslovite, michenerite, penroseite, pyrite, sperrylite, testibiopalladite,
trogtalite, vaesite, and villamaninite.
a. Various metallic-looking sulfide minerals including iron pyrites
(pyrite); copper pyrites (chalcopyrite); tin pyrites (stannite); white
iron, cockscomb, or spear pyrites (marcasite); arsenical pyrites
(arsenopyrite); cobalt pyrites (linnaeite); magnetic pyrites (pyrrhotite);
and capillary pyrites (millerite). Without qualification it popularly
refers to pyrite.
b. Stones that may be used for striking fire.
Common name for chalcopyrite. Weed, 1
Of, pertaining to, resembling, or having the properties of pyrites.
Standard, 2
Smelting of sulfide copper ores, in which heat is supplied mainly by
oxidation of iron sulfide. Syn:oxidizing smelting
The part of the sulfur in coal that is in the form of pyrites or
marcasite. BS, 1
Containing or producing pyrite. Webster 3rd
Introduction of or replacement by pyrite; e.g., the replacement of
original fossil material by pyrite. A common hydrothermal introduction of
pyrite specks in rock adjacent to veins.
An isometric closed crystal form of 12 faces, each an irregular pentagon.
It is named after pyrite, which characteristically has this crystal form.
See also:rhombic dodecahedron CF:dodecahedron
See:kermesite
A trigonal mineral, Mg6 Fe2 (CO3 )(OH)16 .4H
2 O ; hydrotalcite group; dimorphous with sjoegrenite; occurs in
goldlike submetallic scales, or brown crystals having pearly to greasy
luster. A silvery white variety is called igelstromite.
An orthorhombic mineral, PbMn(VO4 )(OH) ; descloizite group; forms
minute fire-red acicular crystals at Laangban, Sweden; a source of
vanadium.
Any of the dark-colored, fairly hard, nonvolatile, carbon-rich material
substances composed of hydrocarbon complexes, which may or may not contain
oxygenated substances and are often associated with mineral matter. The
nonmineral constituents are infusible, insoluble in water, and relatively
insoluble in carbon disulfide. AGI
Pertaining to substances that yield bitumens upon heating. AGI
a. An isometric mineral, (Ca,Na)2 Nb2 O6 (OH,F) ;
forms a series with microlite; in pegmatites in Maine, California,
Colorado, Africa, and Europe; a source of niobium. Syn:pyrrhite
b. The mineral group including the betafite subgroup betafite,
plumbobetafite, and yttrobetafite; the microlite subgroup bariomicrolite,
bismutomicrolite, microlite, plumbomicrolite, and uranmicrolite; and the
pyrochlore subgroup bariopyrochlore, ceriopyrochlore, kalipyrochlore,
plumbopyrochlore, uranpyrochlore, and yttropyrochlore.
A trigonal mineral, Mn(OH)2 ; brucite group; soft; pearly white
darkening on exposure; has perfect basal cleavage.
An individual particle ejected during a volcanic eruption. It is usually
classified according to size. AGI