Gold and Silver: Comprising an Economic History of Mining in the United States, the Geographical and Geological Occurrence of the Precious Metals, with Their Mineralogical Associations, History and Description of Methods of Mining and Extraction of Values, and a Detailed Discussion of the Production of Gold and Silver in the World and the United StatesJ. Wiley & Sons, 1908 - 727 strani |
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Zadetki 1–5 od 100
Stran 25
... usually lie in this bordering zone . Masses of native copper with pieces of native silver attached have been found in the mounds of the Mississippi valley , which would . seem to indicate that the Indians were not acquainted with ...
... usually lie in this bordering zone . Masses of native copper with pieces of native silver attached have been found in the mounds of the Mississippi valley , which would . seem to indicate that the Indians were not acquainted with ...
Stran 108
... usually considered to mark the beginning of actual mining oper- ation in the district.1 The silver - bearing sandstones of Silver Reef , Washington County , were discovered by John Barker in 1873. It is said that the pres- ence of ...
... usually considered to mark the beginning of actual mining oper- ation in the district.1 The silver - bearing sandstones of Silver Reef , Washington County , were discovered by John Barker in 1873. It is said that the pres- ence of ...
Stran 158
... usually occurs in the form of scales and grains and even laminated ; this it is claimed could not be the case were the gold chemically combined with the sulphur . It is well known that pyrite may be produced by the action of a reducing ...
... usually occurs in the form of scales and grains and even laminated ; this it is claimed could not be the case were the gold chemically combined with the sulphur . It is well known that pyrite may be produced by the action of a reducing ...
Stran 161
... usually assays higher than the reef - gold of the same district ? " 1 It is known that weak solutions of gold chloride will dissolve pyrite , but not so fast as to hinder the deposition of metallic gold upon the crystal . Galena is ...
... usually assays higher than the reef - gold of the same district ? " 1 It is known that weak solutions of gold chloride will dissolve pyrite , but not so fast as to hinder the deposition of metallic gold upon the crystal . Galena is ...
Stran 164
... usually found to have fairly well defined limits though extremely irregular , and in certain cases de- pending largely upon the question of economic working . Further , massive rocks when gold - bearing usually have suffered alteration ...
... usually found to have fairly well defined limits though extremely irregular , and in certain cases de- pending largely upon the question of economic working . Further , massive rocks when gold - bearing usually have suffered alteration ...
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Alaska amalgamation andesite argentiferous assay auriferous average bed-rock blende calcite California Carolina cent chalcopyrite chlorination Colorado Comstock lode considerable copper country-rock County Cripple Creek cyanide cyanide process Deep Mines deposits depth diorite discovered discovery district dollars drift employed extraction feet free-gold furnace galena gangue gold and silver gold production gold-bearing granite gravel gray copper Gulch Hill hydraulic Ibid Idaho igneous rocks inches iron Jour lead limestone located mercury method Mexico mill Mineral Industry Mineral Resources Mines and Minerals Montana Mountain Nevada North North Carolina occur operations ore-bodies ounces output oxide placer mines placers porphyry precious metals Press probably production of gold pyrite quantities quartz quartz-veins Rept River roasting rocks schists shaft silver production Silver-bearing slate sluices smelting solution South stamps stope sulphides sulphurets surface TABLE tellurides tellurium tetrahedrite timber tion tons Total tunnel usually Utah veins width yield zinc