Manual of MineralogyDurrie & Peck, 1855 - 432 Seiten |
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Häufige Begriffe und Wortgruppen
actinolite affords alumina antimony apatite arsenic bismuth blende blowpipe blue borax brittle brown calamine calc spar called carbonate cent charcoal chlorid chlorite clay cleavage coal cobalt color Composition consists contains copper pyrites Cornwall crystals dark distinguished earthy epidote feldspar fibrous flame fluor fumes furnace fus dif fuses fusible galena garnet glass globule gneiss gold grains granite granular gray gray copper green heated heavy spar hornblende Infusible iron pyrites lead lime limestone Luster vitreous magnesia magnetic iron manganese masses massive metal mica mineral mines native nearly nickel nitric acid obtained occurs octahedrons odor opaque oxyd oxyd of iron p'ly peroxyd potash pounds Prim protoxyd of iron pyroxene quartz rhombic prisms rocks salt scapolite serpentine silica silver soda sometimes species specific gravity sphene streak strl sulphate sulphuret talc tourmaline translucent transparent usually variety yellow zinc
Beliebte Passagen
Seite 49 - I.) ; hence the sum of all the angles, both interior and exterior, is equal to twice as many right angles as there are sides to the polygon. But the sum of the interior angles alone, less four right angles, is equal to the same sum (Prop.
Seite 81 - The rocks in which the diamond occurs in Brazil are either a ferruginous quartzose conglomerate, or a laminated granular quartz called Itacolumite. The latter rock occurs in the Urals, and diamonds have been found in it ; and it is also abundant in Georgia and North Carolina. In India the rock is a quartzose conglomerate.
Seite 275 - Dissolves in heated nitric acid, with a precipitation of the sulphur. Dif. The vitreous copper ore resembles vitreous silver ore ; but the luster of a surface of fracture is less brilliant, and they afford different results before the blowpipe. The solution made by putting a piece of the ore in nitric acid, covers an iron plate (or knife blade) with copper, while a similar solution of the silver ore covers a copper plate with silver. Obs. Occurs with other copper ores in beds and veins. At Cornwall,...
Seite 136 - They arise from disseminated oxyd of iron ; all the varieties of agate are beautiful stones when polished, but are not much used in fine jewelry. The colors may be darkened by boiling the stone in oil, and then dropping it into sulphuric acid. A little oil is absorbed by some of the layers, which becomes blackened or charred by the acid.
Seite 91 - The place is now protected by a strong building, and the workmen are required to put on a working dress in an apartment on going in and take it off on coming out. In an inner room two men are seated at a large table...
Seite 84 - ... those with curved faces are much the best. Diamond dust is used to charge metal plates of various kinds for jewelers, lapidaries and others. Those diamonds that are unfit for working, are sold for various purposes, under the name of bort.
Seite 160 - Plantes of Paris, for which he gave £3000 sterling. The largest oriental ruby known was brought from China to Prince Gargarin, governor of Siberia ; it afterwards came into the possession of Prince Menzikoff, and constitutes now a jewel in the imperial crown of Russia.
Seite 192 - ... and Grafton, New Hampshire. Other good localities are Paris, Me. ; Chesterfield, Barre, Brimfield, and South Royalston, Mass. ; near Greenwood furnace, Warwick and Edenville, Orange county, and in Jefferson and St. Lawrence counties, NY ; Newton and Franklin, NJ ; near Germantown, Pa., and Jones's Falls, Maryland. Oblique prisms from near Greenwood are sometimes six or seven inches in diameter. A green variety occurs at Unity, Maine, near Baltimore, Md., and at Chestnut Hill, Pa. Prismatic mica...
Seite 189 - The red tourmalines, when transparent and free from cracks, such as have been obtained at Paris, Me., are of great value and afford gems of remarkable beauty. They have all the richness of color and luster belonging to the ruby, though measuring an inch across. A Siberian specimen of this variety, now in the British museum, is valued at £500. The yellow tourmaline, from Ceylon is but little inferior to the real topaz, and is often sold for that gem. The green specimens, when clear and fine, are...
Seite 311 - ... hammer. The pyrites when pounded are reduced to powder ; iron pyrites is too hard to yield at all to a knife, and copper pyrites affords a dull greenish powder. Moreover, the pyrites give off sulphur when strongly heated, while gold melts without any such odor.