IMPORTANT ORE MINERALS

Most elements need to be concentrated into amounts that can be economically mined from ore deposits (usually hundreds to thousands of times their crustal abundance). This concentration is usually accomplished by dissolution of the element by hot water (hydrothermal ore deposits - gold, silver, lead), preferential crystallization from magmas (chromite deposits or pegmatites), surface weathering and leaching (aluminum, nickel, copper), or gravity separation of minerals during erosion (gold, diamonds, titanium). In the majority of cases there are only one or two minerals that provide all of a particular element for commercial uses. Some elements in low concentrations (substituting in minor amounts for the major elements) are associated with minerals that are mined for other elements, but the shear volumes of materials that are processed result in a valuable byproduct (i e. elements associated with copper, lead, and zinc ores). Some elements are so valuable that almost any mineral containing that element in sufficient grades can be mined (gold, silver, platinum group).

ELEMENTS

Aluminum - The ore is mined from rocks that have been exposed to weathering in a tropical environment, bauxite. The main ore minerals in bauxite are gibbsite, bohmeite, and diaspore.

Antimony - The primary ore of antimony is it's sulfide, stibnite.

Arsenic - Recovered from other metal processing streams (primarily from the sulfosalts such as tennantite etc.). Arsenopyrite is the most common arsenic mineral. The relatively low demand for arsenic as compared to the amount of arsenic mined that is associated with other metals means it can be supplied from the waste streams of other ore processing.

Barium - The chief source of barium is barite with minor production of witherite.

Beryllium - The major ore mineral for beryllium in the U.S. is bertrandite while worldwide the major source is from pegmatites that contain beryl.

Bismuth - Primarily a byproduct of lead processing. Also found in a number of minerals such as bismuthinite and as a constituent in various sulfosalts.

Boron - Chief source is playa lake deposits of borax, colemanite, kernite, ulexite.

Bromine - Chief sources are brines from wells and Dead Sea.

Cadmium - Unlike many other commodities cadmium is produced as a byproduct of zinc (sphalerite) mining.

Cesium - The major ore mineral is pollucite, a pegmatite mineral. Production and use of this metal is extremely small (a few thousand kilograms per year).

Chlorine - Produced from the mineral halite (rock salt).

Chromium - The chief source is the mineral chromite which is found in large layered intrusives and serpentine bodies.

Cobalt - The primary minerals for cobalt is cobaltite. Some cobalt is also produced from weathered tropical orebodies.

Columbium (see Niobium)

Copper - Most copper ore bodies are mined from minerals created by weathering of the primary copper ore mineral chalcopyrite. Minerals in the enriched zone include chalcocite, bornite, djurleite. Minerals in the oxidized zones include malachite, azurite, chyrsocolla, cuprite, tenorite, native copper and brochantite.

Gallium - A byproduct of zinc and alumina processing. Some primary "ore" may contain up to 200 ppm. Ga.

Germanium - A byproduct of zinc ore processing. Also a deposit in China is associated with coal.

Gold - The primary mineral of gold is the native metal and electrum (a gold-silver alloy). Some tellurides are also important ore minerals such as calaverite, sylvanite, and petzite.

Hafnium - Primary ore mineral is zircon.

Indium - Primarily is a byproduct of zinc processing.

Iodine - Initial production was from seaweed. Iodine is extracted from natural gas field brines (up to 1200 ppm iodine in the brines).

Iron - Two major minerals in the production of iron are it's oxides, hematite and magnetite. These are found in preCambrian iron formations. Historically there was also production from goethite and siderite. The iron sulfides (pyrite and pyrrhotite) were not used as iron sources due to the difficulty of removing sulfur from the metals and the brittleness this sulfur caused in the metal.

Lead - The primary ore mineral for lead is it's sulfide - galena. Some minor production from the past has come from secondary lead minerals - cerussite and anglesite.

Lithium - The former primary ore minerals were pegmatite deposits of spodumene, lepidolite, and petalite, amblygonite. Currently the major U. S. production is from lithium carbonate brines.

Magnesium - Although magnesium is found in many minerals, only dolomite, magnesite, brucite, carnallite, and olivine are of commercial importance. Magnesium and other magnesium compounds are also produced from seawater, well and lake brines and bitterns.

Manganese - The primary ores are oxides/hydroxides of manganese which include minerals such as hausmannite, pyrolusite, braunite, manganite, etc. and the carbonate, rhodochrosite. A large potential source is the deep sea manganese nodules.

Mercury - The main ore is the sulfide, cinnabar.

Molybdenum - The primary ore mineral is molybdenite.

Nickel - The primary nickel ores are pentlandite, nickel bearing pyrrhotite and a weathering product, garnierite (a mixture of népouite, pecoraite and willemseite).

Niobium (Columbium) - The primary ore mineral is pyrochlore with minor columbite and tantalite-columbite.

Phosphorus - Main ore minerals are in the apatite group of minerals (hydroxylapatite, fluorapatite, chlorapatite).

Platinum group (Platinum, Osmium, Rhodium, Ruthenium, Palladium) - The primary ores are the native elements or alloys of the various elements or arsenides such as sperrylite. They tend to occur in layered intrusives associated with chromite deposits.

Potassium (potash) - The primary ore minerals are sylvite (primarily), brines, and langbeinite.

Rare Earth elements (cerium, dysprosium, erbium, europium, gadolinium, holmium, lanthanium, lutetium, neodymium, praseodymium, samarium, scandium, terbium, thulium, ytterbium, yttrium) The major ore minerals containing rare earth elements are bastnasite, monazite, and loparite and the lateritic ion-adsorption clays. Major U.S. production of bastnesite is from Mountain Pass, California.

Rhenium - Produced as a byproduct of molybdenite.

Rubidium - Substitutes for potassium in lepidolite and pollucite. Production is small (a few thousand kilograms per year).

Scandium (see Rare Earth)

Selenium - Recovered from copper processing.

Silicon - The primary source is quartz.

Silver - Silver production has been from the sulfide argentite/acanthite, native silver, sulfosalts such as pyrargyrite and proustite, chloride as cerargyrite. It is also found in small amounts in some tetrahedrites.

Sodium - Principle resources are halite (rock salt) or soda ash (see below).

Strontium - Main ore mineral is celestite, with minor production of strontianite.

Sulfur - Major production is from desulferizing natural gas and petroleum. Sulfuric acid is produced from the flue gases of metal smelters. Historically, sulfur was produced from native sulfur and pyrite.

Tantalum - Primarily from tantalite-columbite although minor amounts are found in tin concentrates.

Tellurium - Recovered in processing copper ores.

Thallium - Recovered from processing copper, lead and zinc ores.

Thorium - Recovered primarily from monazite.

Tin - Primary ore is cassiterite.

Titanium - Usually produced from placer deposits, the ore minerals are rutile, ilmenite, and leucoxene.

Tungsten - Primary ore minerals are scheelite and huebnerite-ferberite.

Uranium - The chief primary ore minerals are uraninite, pitchblende (a mixture of various oxides), coffinite and a host of secondary minerals such as carnotite and autunite.

Vanadium - Recovered from petroleum residues also produced from vanadium bearing magnetite rocks. In the past it was recovered from minerals in uranium deposits.

Zinc - The primary zinc ore mineral is sphalerite, zinc sulfide. Some past production has been from smithsonite and hemimorphite.

Zirconium - Major source is the mineral zircon.

INDUSTRIAL MINERALS

Abrasives, natural - Diamonds, garnets (almandine, pyrope and andradite), corundum (emery).

Barite - A major use for barite is as a weight increasing additive for drilling oil and gas wells.

Calcite - A major source for this mineral is limestone. It has been used for the manufacture of cement, application to agricultural lands for pH control, as a building material, and crushed for gravel.

Clays - Used in the manufacture of bricks, tiles and as a filler for paper etc.

Attapulgite
Ball Clay
Bentonite
Calcium Bentonite
Common Clay
*Minerals Fire Clay
Hectorite*
Kaolinite*
Meerschaum
Palygorskite*
Refractory Clay
Saponite*
Sepiolite*
Shale
Sodium Bentonite

Feldspars - Used in manufacture of glass, ceramics and enamels. Includes orthoclase, microcline, and albite (member of the plagioclase series).

Gemstones - The most valuable total gemstone production is diamond; corundum varieties, ruby and sapphire; beryl varieties emerald, aquamarine, and kunzite. Many other semiprecious gemstones are mined for decorative and jewelry use.

Gypsum - A major source for Portland cement, plaster of Paris, a soil conditioner, and an important component in drywall.

Perlite - Used in lightweight aggregates.

Soda Ash (sodium carbonate) - Primary production from trona, nahcolite and brines.

Zeolites - The primary natural production of zeolites include the minerals chabazite, clinoptilolite, and mordenite.

Miscellaneous mineral production - wollastonite, vermiculite, talc, pyrophyllite, graphite, kyanite, andalusite, muscovite, and phlogopite.

For more information see the United States Geological Survey website on mineral production (the source for most of this information).


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