Pitchblende or uraninite, consists mostly of uranium oxides. It is a pitch-black, greenish or brownish black mineral, green or brown when finely powdered; it has a smooth or conchoidal break, and is very heavy. Pitchblende is found in pegmatite dikes, sometimes, as in Cornwall, England, associated with tinstone. Other uranium minerals of similar appearance, euxenite and … Read more
Titanium The ores of Titanium are rutile (TiO2), and ilmenite (FeTiO3). Rutile has been found in quantity in gabbro-pegmatite along with apatite; also with ilmenite in anorthosite. The red or reddish-brown crystals (Fig. 39) of rutile are not likely to be overlooked; it is used mostly in electrodes of are lamps. The market price for rutile … Read more
The iron minerals that are at present used as ores are hematite, magnetite, limonite, and siderite; also, occasionally ankerite, goethite, and turgite. Hematite is the most important iron ore. The iron content of the pure minerals is as follows: Ankerite is a carbonate of lime, magnesia, manganese, and iron. It is of … Read more
Copper Copper ores are found in a great variety of formations. Native copper occurs in trap, particularly the amygdaloidal variety; it is deposited in the amygdules and in veinlets and joints. At the surface, the copper may show its presence by the green and blue stains of the carbonates, malachite and azurite. The neighborhood of … Read more
Where to Explore for Mercury Minerals The principal ore of mercury is cinnabar, HgS, known by its bright red color (vermilion-red when powdered), its great weight, and its softness. Cinnabar is found in irregular veins, breccia zones, stockworks, and disseminations in rocks of all kinds and ages in regions of present or past volcanic activity; the … Read more
Silver The silver production of Canada has been mostly from two classes of deposits: those of the Cobalt district where the silver is largely native and associated with cobalt and nickel arsenides; and the silver-lead deposits of British Columbia. Silver is likewise produced in considerable quantities in British Columbia from certain gold and copper ores; … Read more
Placer Gold Placer deposits of gold are formed by the concentration of the gold from the debris of gold veins and other deposits of gold in rock. As the loose material is washed down hillsides into gullies and valleys, the gold, being six or seven times as heavy as quartz and other rock- minerals, quickly … Read more
The complete study of faulting belongs to mining rather than to prospecting. But there are surface results of importance to the prospector. As explained, faulting is due to the breaking of the rock under strain; there has been displacement at the same time, so that the two sides of the break do not fit. If the … Read more
Mechanical Deposition of Sedimentary Mineral Deposits In some cases, the ore mineral, on account of its resistance to weathering and its hardness, survived the destruction of many of the rock minerals; and, during sedimentation, on account of its weight, it was sorted out from the fragments of quartz and other resistant minerals. Thus, the ore-mineral was deposited, … Read more
Vein Mineral Deposits includes a considerable variety of ore deposits formed under various conditions by the concentration of the ore from the molten rock in process of cooling, and its subsequent deposition in fissures and joints, crevices, and pores; or the accompanying solvents make room for the ore by dissolving the rock and carrying it … Read more