It is often said that this saline change is more characteristic of marcasite than of pyrite, but according to H.
The mining product next in value to coal in 1908 was copper, taken chiefly in Carbon county in a zone of brecciated quartzite underlying schist, the original ore being chalcopyrite, with possibly some pyrite, a secondary enrichment, which has produced important bodies of chalcocite in the upper workings, but these are replaced by chalcopyrite at greater depth.
Stokes, "On Pyrite and Marcasite," Bull.
Other mineral products are graphite, garnet used as an abrasive, pyrite and zinc ore.
Finely crystallized specimens of pyrite are obtained from many other localities, especially from Cornwall, Elba and Traversella, near Ivrea, in Piedmont.
Pyrite, FeS2, contains 46.7% of iron.
In the case of coal, salt, iron ore, pyrite and other homogeneous minerals, boring may give all the information required.
Other mineral substances obtained in small quantities are: pyrite, in St Lawrence county; arsenical ore, in Putnam county; red, green and purple slate, in Washington county; garnet in Warren, Essex and St Lawrence counties; emery and felspar, in Westchester county; and infusorial earth in Herkimer county.
For chemical means of distinguishing pyrite from marcasite consult H.
Impurities.-The properties of iron and steel, like those of most of the metals, are profoundly influenced by the presence of small and sometimes extremely small quantities of certain impurities, of which the most important are phosphorus and sulphur, the former derived chiefly from apatite (phosphate of lime) and other minerals which accompany the iron ore itself, the latter from the pyrite found not only in most iron ores but in nearly all coal and coke.
The two assertions are not to be reconciled by pointing out that Professor Tornebohm underestimated, for instance crediting the United States with only 1 1 billion tons, whereas the United States Geological Survey's expert credits that country with from ten to twenty times this quantity; nor by pointing out that only certain parts of Europe and a relatively small part of North America have thus far been carefully explored for iron ore, and that the rest of these two continents and South America, Asia and Africa may reasonably be expected to yield very great stores of iron, and that pyrite, one of the richest and most abundant of ores, has not been included.
They are four important iron ores, magnetite, haematite, limonite and siderite, and one of less but still considerable importance, pyrite or pyrites.
Rickard, Pyrite Smelting (1905); for wet methods, see Eissler, Hydrometallurgy of Copper (London, 1902); and for electrolytic methods, see T.
In marls, cement-stones and argillaceous limestones); (4) sulphide of iron, as pyrite or marcasite (when finely diffused, giving the clay a dark grey-blue colour, which weathers to brown - e.g.
Glass and other sands and gravel ($13,270,032), lime ($11,091,186), phosphate rock ($10,653,558), salt ($7,553,632), natural mineral waters ($7,287,269), sulphur ($6,668,215, almost wholly from Louisiana), slate ($6,316,8 I7), gypsum ($4,138,560), clay ($2,599,986), asphalt ($1,888,881), talc and soapstone ($1,401,222), borax ($975,000, all from California), and pyrite ($857,113) were the next most important products in 1908.
Sometimes, however, the term pyrites is loosely applied to both species, and the cubic pyrites is then differentiated by the name "pyrite" - a form which brings the last syllable into harmony with the spelling of the names of most minerals.
Contrary, too, to popular belief, he has found a fibrous structure more common in pyrite than in marcasite.
Iron pyrites, or pyrite, belongs crystallographically to the parallelfaced hemihedral class of the cubic system.
The Federal government completed in October 1907 the construction of a 1 According to the report of the State Geological Survey, the value of the total mineral product in the state for 1907 was $152,122,648, the values of the different minerals being as follows: coal, $54,687,382; pig iron, about $52,228,000; petroleum, $ 16, 43 2, 947; clay and clay products, $13,351,362; zinc, $6,614,608; limestone, $4,333,651; Portland cement, $2,632,576; sand and gravel, $1,367,653; natural slag, $174,282; fluorspar, $141,971; mineral waters, $91,700; lead ore, $45,760; sandstone, $14,996; and pyrite, $5700.
It occurs in nature as the mineral melanterite, either crystalline or fibrous, but usually massive; it appears to have been formed by the oxidation of pyrite or marcasite.
Though it contains far too much sulphur to be used in iron manufacture without first being desulphurized, yet great quantities of slightly cupriferous pyrite, after yielding nearly all their sulphur in the manufacture of sulphuric acid, and most of the remainder in the wet extraction of their copper, are then used under the name of " blue billy " or " purple ore," as an ore of iron, a use which is likely to increase greatly in importance with the gradual exhaustion of the richest deposits of the oxidized ores.
Pyrite may be prepared artificially by gently heating ferrous sulphide with sulphur, or as brassy octahedra and cubes by slowly heating an intimate mixture of ferric oxide, sulphur and salammoniac. It is insoluble in dilute acids, but dissolves in nitric acid with separation of sulphur.
In the production of pyrite, which is found in Louisa county and is used for the manufacture of sulphuric acid employed in the treatment of wood pulp for paper-making and in the manufacture of superphosphates from phosphate rock, Virginia took first rank in 1902 with an output valued at $501,642, or 64.7% of the total yield of this mineral in the United States; and this rank was maintained in 1908, when the product was 116,340 long tons, valued at $435,522.
Iron disulphide, FeS2, constitutes the minerals pyrite and marcasite; copper pyrites is (Cu, Fe)S2.