Pyrite : Chalcopyrite
The mineral pyrite or iron pyrite is iron disulfide, FeS2, its isometric crystals usually appearing as cubes or pyritohedrons. It has a slightly uneven and conchoidal fracture, a hardness of 6-6.5, and a specific gravity of 4.95-5.10. Its metallic lustre and pale to normal brass-yellow color have earned pyrite the name "fool's gold," but ironically enough small quantities of actual gold can sometimes be found in pyrite (to the point where some auriferous pyrite is a very valuable ore), as well as arsenic, nickel, cobalt and copper.
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A mass of interwoven pyrite crystals, 11 cm (4.0 in) long Larger version |
Pyrite is the commonest of the sulfide minerals, and is found world-wide. It is found associated with other sulfides, or with oxides, in quartz veins, in sedimentary rock and metamorphic rock, in coal beds, and as the replacement mineral in fossils. Pyrites, interestingly, can show negative resistance, acting as radio detectors and have been used in oscillator circuits (http://home.earthlink.net/~lenyr/iposc.htm).
Pyrite is used in the production of sulfur dioxide for the paper industry and in the manufacture of sulfuric acid, though not as much as it used to be. The name pyrite is from the Greek word meaning fire. because of the sparks that result when pyrite is struck with steel.
See also: List of minerals
Was it not the spirit that counted? Yet Mrs. Blythe was hard
question the wisdom of the Almighty any more as I have been doing
anywhere. We have just got to grapple with whatever we have to do
shall grapple. Those blessed boys have gone to war; and we women, Mrs.
don't like it--I don't like it."
"Do not you lose heart, Dr. dear; they were just defended by
against the British; there will be a very different story to tell and
all shared subconsciously in Susan's belief that "the thin grey line"
millions. At any rate, when the terrible day came--the first of many
stared at each other in blank dismay.
"It--it can't be true," gasped Nan, taking a brief refuge in temporary
cat-creature turned into Mr. Hyde this morning without rhyme or reason
doctor, from a London dispatch. "Can it be England's army of which such
despairingly.
Susan's faith, which had for a moment been temporarily submerged, now
Never forget that. And the Russians are on their way, too, though
tie to."
"The Russians will not be in time to save Paris," said Walter gloomily.
--he stopped abruptly and went out.
After a paralysed day the Ingleside folk found it was possible to "carry
in her kitchen, the doctor went out on his round of visits, Nan and Di
Charlottetown to attend a Red Cross Convention; Rilla after.
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