Website design By BotEap.comSilver has been above $10 an ounce for the better part of a year, making some people curious about where silver came from. Silver is mined from a variety of rock-like minerals, commonly in combination with gold. In some ores gold predominates, but in others it is silver, while in a third class these two precious metals may be mixed with various common metals, such as lead, copper, zinc, and iron. Few silver ores are absolutely free of gold, and vice versa, so a separate consideration of the two is more or less a tall order. For those minerals where the most valuable element is silver, silver is normally contained in minerals that have a gray to black appearance. These minerals range from those with a metallic luster to others with an earthy, soot-like appearance. Sooty black minerals are common in many very rich silver ore samples. Most of these sooty black deposits consist of acanthite or various silver-bearing complex sulfides (a sulfide is a mineral that contains sulfur in combination with one or more metals).

Website design By BotEap.comThe most common valuable minerals that can make up rich silver ores include native silver; acanthite (silver sulfide); pyargyrite (dark ruby ​​silver or silver antimony sulfide); Proustite (light ruby ​​silver or silver arsenic sulfide); Stephanite (brittle silver, also a silver antimony sulfide); Polybasite (also a sulfide of silver and antimony); cerargyrite (silver chloride); Bromyrite (silver bromide) and Yodirite (silver iodide). Bonanza grade silver ore may also contain various silver telluride minerals, including Calaverite, Sylvanite, and Hessite. To a lesser extent, base metal sulfides, including galena, sphalerite, pyrite, chalcopyrite, and chalcocite, can and often do contain silver, but in most silver ore deposits, silver it is more concentrated in the minerals of the group mentioned above. Of the base metal ores, the most common primaries are silver galena, sphalerite, and pyrite, while native silver and sulfides and arsenides are less common.

Website design By BotEap.comStandard types of silver ores:

Website design By BotEap.comThere are two general classes of silver ore that have been mined: 1) lead-silver and 2) high-grade silver ores. Both almost always have variable amounts of gold. Lead and silver mines also supply, as noted above, by far the majority of the lead produced in the United States. High-grade silver ores typically have considerably lower base metal content and often contain a significant amount of gold.

Website design By BotEap.com1. Dry or siliceous minerals. These include: (a) Gold and silver ores proper, including bonanza epithermal silver ores; (b) flux ores containing considerable amounts of oxides of iron and manganese with small contents of gold and silver; (c) minerals containing precious metals with copper, lead and zinc in small amounts; and (d) disseminated low-grade silver deposits. The states of Colorado, California, Nevada, South Dakota and Alaska have been the largest producers of this category of silver ore. The siliceous minerals are partly free milled; partly just concentrating, like parts of Colorado and Arizona; partly growing slimming and cyaniding; and partly foundry. Much of the silver in siliceous gold and silver ores is obtained with gold by cyanidation, with the silver being recovered by refining mill ingots. The rest is obtained by smelting rich ores and refining the copper or lead ingots produced. Siliceous silver minerals are of variable ages, but most epithermal minerals are young, typically post-Miocene in age. Those found primarily in Colorado, Nevada, and Montana are associated with Tertiary lavas and are characterized by rich Bonanza-grade minerals. Some of the most productive can carry fluorspar and usually also tellurides. In some, the value of gold may predominate; in others, silver.

Website design By BotEap.com2. Copper ores, generally greater than 1 percent copper, but less for Western disseminated and Lake Superior ores. The largest gold producers are those of Utah, Arizona, Nevada and Montana. Silver production comes from electrolytic refining of blister copper produced by smelting. Large scattered deposits in Utah, Arizona, Nevada and New Mexico are producing increasing amounts, while lode deposits in places like Butte, Mont., have also been important. Copper ores containing gold and silver exhibit great differences in shape and age; neither do all occurrences give much gold or silver, and, moreover, they are of greater importance as producers of gold, silver being less associated with copper.

Website design By BotEap.com3. Lead-containing silver ores: These are silver ores that contain 4 percent or more lead. Silver comes primarily from the lead and silver ores of Coeur d’Alene, Idaho, Utah (mainly Park City and Tintic), Colorado (Leadville and Aspen). Most of the production is obtained through the desilverization of lead ingots using molten zinc. The silver and lead ores form a large class, fairly widely distributed, and although the two metals that characterize the group are the most prominent, there can also be, and often are, a variable amount of other metals such as gold, zinc, and copper. Silver contents, although sometimes high, are not necessarily visible and may be contained within the galena as Ag2S which partially replaces the lead sulfide in the crystal. The ore bodies as a whole present a variety of shapes, the ore having been deposited either by fill or replacement of the fissure vein cavity, or both. Most of the important occurrences appear to have formed at intermediate depths. Oxidation zones frequently overlay ore bodies, and in many cases secondary downstream enrichment has likely occurred. Silver and lead ores form a class widely distributed in the Cordilleran region of the United States and supply most of the lead mined in this country. Prominent deposits have been mined in Colorado, Idaho, and Utah, but are also known from New Mexico, Montana, Wyoming, Nevada, Arizona, California, and South Dakota. Canada provides a small but steady output from British Columbia, while in other foreign countries, districts noteworthy for commercial or historical significance are Broken Hill, New South Wales, Australia; Clausthal and Freiberg, Germany; Przibram, Bohemia; Hall, Sweden; Laurium, Greece; Mexico etc

Website design By BotEap.com4. Copper-lead or copper-lead-zinc ores. These are not important compared to the others. The gold they supply is small, and the main silver production came from mines in Colorado and Nevada. Historically, the Eureka District of Nevada produced significant amounts of copper, lead and zinc ore with large amounts of gold and silver. They are often designated as polymetallic minerals in modern classification systems.

Website design By BotEap.com5. Zinc ores, containing at least 25 percent zinc. These produce little gold, and silver which is obtained mainly as a by-product of zinc concentrate smelting and in the United States has been obtained mainly from deposits in Nevada, Montana and Arizona.