Cambrian, Ordovician and Silurian beds have been recognized, the Upper Cambrian consisting of a limestone which is very rich in metalliferous ores (especially galena and calamine).
The government let the mines to contractors for forty years and then took them over; but in the period from 1720 to 1840 only 14,620 tons of galena were extracted and 2772 of lead.
The most important minerals are lead and zinc, obtained in lodes in the forms of galena and calamine respectively.
The lodes are most frequently of great size, containing huge masses of galena, and so little gangue that the ore can very easily be dressed to 83 or 84%.
1 The minerals produced are tin, gold, iron, galena and others, in insignificant quantities.
Also several contacts, such as that of galena (sulphide of lead) and 1 See J.
Free sulphur may also result from the decomposition of pyrites, as in pyritic shales and lignites, or from the alteration of galena: thus crystals of sulphur occur, with anglesite, in cavities in galena at Monteponi near Iglesias in Sardinia; whilst the pyrites of Rio Tinto in Spain sometimes yield sulphur on weathering.
Copper pyrites (copper), galena (lead), blende (zinc), cinnabar (mercury), &c. Of the sulphates we notice gypsum and anhydrite (calcium), barytes (barium) and kieserite (magnesium).
Galena is found in small quantity, and in some places it contains a large percentage of silver.
Considerable quantities of the following minerals have been found: barytes (heavy spar), magnetite (magnetic iron ore), and pyrolusite (manganese dioxide) in Humboldt county; roofing slate in Esmeralda county; cinnabar (ore containing quicksilver) in Washoe county; haematite in Elko and Churchill counties; cerussite and galena (lead ores) in Eureka county; and wolframite (a source of tungsten) at Round Mountain, White Pine county.
Galena and other lead ores are abundant in veins in the limestone, but they are now only worked on a large scale at Mill Close, near Winster; calamine, zinc blende, barytes, calcite and fluor-spar are common.
Galena and other lead ores are abundant in veins in the limestone, but they are now only worked on a large scale at Mill Close, near Winster; calamine, zinc, blende, barytes, calcite and fluor-spar are common.
The ores found here comprise silver-free galena, sulphate of zinc and calamine.
Many substances were employed in ancient medicine: galena was the basis of a valuable Egyptian cosmetic and drug; the arsenic sulphides, realgar and orpiment, litharge, alum, saltpetre, iron rust were also used.
The chief lead ores are galena and cerussite; of minor importance are anglesite, pyromorphite and mimetesite (qq.v.).
Galena (q.v.), the principal lead ore, has a world-wide distribution, and is always contaminated with silver sulphide, the proportion of noble metal varying from about o of or less to o 3%, and in rare cases coming up to 2 or i %.
Fine-grained galena is usually richer in silver than the coarsegrained.
Galena occurs in veins in the Cambrian clay-slate, accompanied by copper and iron pyrites, zinc-blende, quartz, calcspar, iron-spar, &c.; also in beds or nests within sandstones and rudimentary limestones, and in a great many other geological formations.
All native carbonate of lead seems to be derived from what was originally galena, which is always present in it as an admixture.
The extraction of the metal from pure (or nearly pure) galena is the simplest of all metallurgical operations.
The use of the first two is restricted, as they are suited only for galena ores or mixtures of galena and carbonate, which contain not less than 58% lead and not more than 4% silica; further, ores to be treated in the ore-hearth should run low in or be free from silver, as the loss in the fumes is excessive.
Powdered galena is dissolved in hot hydrochloric acid, the solution allowed to cool and the deposit of impure lead chloride washed with cold water to remove iron and copper.
Lead sulphide, PbS, occurs in nature as the mineral galena (q.v.), and constitutes the most valuable ore of llead.
It may also be accompanied by pyrites, galena, arsenides and antimonides, quartz, calcite, dolomite, &c. It is widely distributed, and is particularly abundant in Germany (the Harz, Silesia), Austro-Hungary, Belgium, the United States and in England (Cumberland, Derbyshire, Cornwall, North Wales).
Second in importance is the carbonate, calamine (q.v.) or zinc spar, which at one time was the principal ore; it almost invariably contains the carbonates of cadmium, iron, manganese, magnesium and calcium, and may be contaminated with clay, oxides of iron, galena and calcite; "white calamine" owes its colour to much clay; "red calamine" to admixed iron and manganese oxides.
In,the vicinity of some of the deposits of argentiferous galena are large coal beds, but timber is scarce on the table-lands.
Of other metals, lead is widely distributed, its chief source being a high grade galena accompanied by silver.
In 1860 he removed to Galena, Illinois, and became a clerk in a leather store kept by his father.
He was living at Galena at the outbreak of hostilities between the North and South.
After his return to America in September 1880 he went back to his old home in Galena, Illinois.
Lead ores (chiefly argentiferous galena) and building stone are found, and iron ore is distributed over the hilly country.
Galena, Illinois >>
Argentiferous galena occurs at Sala in limestone, surrounded by granulite, and at Guldsmedshytta (province of Orebro) in dark halleflinta.
Bloomington derives its name from Blooming Grove, a small forest which was crossed by the trails leading from the Galena lead mines to Southern Illinois, from Lake Michigan to St Louis, and from the Eastern to the far Western states.
GALENA, a city and the county-seat of Jo Daviess county, Illinois, U.S.A., in the N.W.
Part of the state, on the Galena (formerly the Fever) river, near its junction with the Mississippi, about 165 m.
It is served by the Chicago, Burlington & Quincy, the Chicago & North-Western and the Illinois Central railways; the Galena river has been made navigable by government locks at the mouth of the river, but the river traffic is unimportant.
Grant, who was a resident of Galena at the outbreak of the Civil War.
In the vicinity there are the most important deposits of zinc and lead in the state, and the city derives its name from the deposits of sulphide of lead (galena), which were the first worked about here; below the galena is a zone of zinc carbonate (or smithsonite) ores, which was the main zone worked between 1860 and 1890; still lower is a zone of blende, or zinc sulphide, now the principal source of the mineral wealth of the region.
Galena was originally a trading post, called by the French "La Pointe" and by the English "Fever River," the river having been named after le Fevre, a French trader who settled near its mouth.
In 1826 Galena was laid out as a town and received its present name; it was incorporated in 1835 and was reincorporated in 1882.
Galena, Kansas >>