Sudbury Basin nickel and copper, Ontario, Canada.Hematite iron ore deposits of altered banded iron formation.Mississippi valley type (MVT) zinc-lead deposits.– Exhalative spilite-chert hosted gold deposits – Stratiform tungsten, typified by the Erzgebirge deposits, Czechoslovakia – Stratiform arkose-hosted and shale-hosted copper, typified by the Zambian copperbelt. – Lead-zinc-silver, typified by Red Dog, McArthur River, Mount Isa, etc. Alluvial oxide zinc deposit type: sole example Skorpion Zinc.Alluvial gold, diamond, tin, platinum or black sand deposits.Heavy mineral sands ore deposits and other sand dune hosted deposits.– Channel-iron deposits or pisolite type iron ore Banded iron formation iron ore deposits, including.Diatreme hosted diamond in kimberlite, lamproite or lamprophyre.Rare earth elements – Mount Weld, Australia and Bayan Obo, Mongolia.Phosphorus-tantalite-vermiculite (Phalaborwa South Africa).Broken Hill Type Pb-Zn-Ag, considered to be a class of reworked SEDEX deposits.Podiform serpentinite-hosted paramagmatic iron oxide-chromite deposits, typified by Savage River, Tasmania iron ore, Coobina chromite deposit.Volcanic hosted massive sulfide (VHMS) Cu-Pb-Zn including Įxamples include Teutonic Bore and Golden Grove, Western Australia.Lateritic nickel ore deposits, examples include Goro and Acoje, (Philippines) and Ravensthorpe, Western Australia.– Intrusive-related Ni-Cu-PGE, typified by Voisey’s Bay, Canada and Jinchuan, China – Subvolcanic feeder subtype, typified by Noril’sk-Talnakh and the Thompson Belt, Canada – Cumulate hard-rock titanium (ilmenite) deposits – Cumulate vanadiferous or platinum-bearing magnetite or chromite Magmatic nickel-copper-iron-PGE deposits including.Skarn ore deposits of copper, lead, zinc, tungsten, etcetera.Hydromagmatic magnetite iron ore deposits and skarns.Intrusive-related copper-gold +/- (tin-tungsten), typified by the Tombstone, Arizona deposits.Porphyry copper +/- gold +/- molybdenum +/- silver deposits.IOCG or iron oxide copper gold deposits, typified by the supergiant Olympic Dam Cu-Au-U deposit.It can also be used to learn about plate tectonics and the movement of continents over time.Ī similar orientation of tiny magnetite grains occurs in the settling of sediment particles, locking clues to Earth's magnetic history into some sedimentary rocks. This information is available for multiple locations on multiple continents. Today, geologists can study the magnetic properties of rocks of various age and reconstruct the history of change in Earth's magnetic field. This preserves the orientation of Earth's magnetic field within the rock at the moment of crystallization. In the crystallization of an igneous rock, tiny crystals of magnetite form in the melt, and because they are magnetic, they orient themselves with the direction and polarity of Earth's magnetic field. Tiny crystals of magnetite are present in many rocks. Small amounts of magnetite are also used as a toner in electrophotography, as a micronutrient in fertilizers, as a pigment in paints, and as an aggregate in high-density concrete. In the past few decades, synthetic abrasives have filled many of the applications where magnetite was previously used. Some finely ground magnetite is also used as an abrasive in waterjet cutting. The production of synthetic emery gives the manufacturer control over the particle size and the relative abundance of aluminum oxide and magnetite in the product. Some synthetic emery is produced by mixing magnetite with aluminum oxide particles. The abrasive known as "emery" is a natural mixture of magnetite and corundum. They can be directly loaded into a blast furnace at a mill and be used to produce iron or steel. These pellets are easy to handle and transport by ship, rail, or truck. The concentrate is then mixed with small amounts of limestone and clay, then rolled into small round pellets. Today's commercial taconites contain 25 to 30% iron by weight.Īt the mine site, the taconite ore is ground to a fine powder, and strong magnets are used to separate magnetically susceptible particles containing magnetite and hematite from the chert. Once considered a waste material, taconite became an important ore after higher grade deposits were depleted. Most of the iron ore mined today is a banded sedimentary rock known as taconite that contains a mixture of magnetite, hematite, and chert. Creative Commons photo by Harvey Henkelmann. The pellets are approximately 10 millimeters in diameter. Taconite pellets: These red spheres are taconite pellets that are ready to ship to a steel mill.