Nickel meteorite

Nickel is found as a constitutent in most meteorites and often serves as one of the criteria for distinguishing a meteorite from other minerals. Iron meteorites, or siderites, may contain iron alloyed with from 5 percent to nearly 20 percent nickel. Nickel is obtained commercially from pentlandite and pyrrhotite of the Sudbury region of Ontario, a district that produces about 30 percent of the world s supply of nicke. 

Gobalt occurs in the minerals cobaltite, smaltite, and erythrite, and is often associated with nickel, silver, lead, copper, and iron ores, from which it is most frequently obtained as a by-product. It is also present in meteorites. 

People have sometimes been able to avoid the tedious business of extracting iron from its natural ore. When Commander Peary was exploring Greenland in 1894 he was taken by an Eskimo to a place near Cape York to see a huge, half-buried meteorite. This had provided metal for Eskimo tools and weapons for over a hundred years. Meteorites usually contain iron plus about 10% nickel a direct delivery of low-alloy iron from the heavens. 

The most important single deposit of nickel is at Sudbury Basin, Canada. It was discovered in 1883 during the building of the Canadian Pacific Railway and consists of sulfide outcrops situated around the rim of a huge basin 17 miles wide and 37 miles long (possibly a meteoritic crater). Fifteen elements are currently extracted from this region (Ni, Cu, Co, Fe, S, Te, Se, Au, Ag and the six platinum metals). 

Fig. 8.38 (Left) The Mossbauer spectrum of the rock called Heat Shield rock, clearly shows with high intensity the mineral Kamacite, an Fe-Ni alloy with about 6-7% Ni (Right) The iron-nickel meteorite Meridiani Planum (originally called Heat Shield Rock ) at Opportunity landing site, close to the crater Endurance. The meteorite is about 30 cm across (Courtesy NASA, JPL, Cornell University)...

Knox, R. (1987), On distinguishing meteoritic from man made nickel-iron in ancient artifacts, Museum Appl. Sci. Center Archaeol.. 4(4), 178-184. 

Another source of information about the elements in outer space comes from meteorites. Meteorites are made of the same elements known on earth, but they have some differences. Iron meteorites are mainly iron mixed with a little nickel, often formed into one huge crystal. Iron does not crystallize the same way on earth. 

Primarily iron and nickel and similar in composition to M-type asteroids iron, 91% nickel, 8.5% cobalt, 0.6%. A recent find of an iron meteorite on the surface of Mars is shown on p. 7 of the colour plate section... 

Iron Class of meteorite dominated by iron and nickel in composition. 

Occurrence. Iron is highly abundant (about 5.5% of the earth s crust) it is believed that the core of earth is mostly molten iron together with nickel. The most common ore is haematite (Fe203). Iron is found in other minerals such as magnetite, limonite, siderite, pyrite. Iron is found native in meteorites known as siderites. 

The most common ore of iron is hematite that appears as black sand on beaches or black seams when exposed in the ground. Iron ores (ferric oxides) also vary in color from brownish-red to brick red to cherry red with a metallic shine. Small amounts of iron and iron alloys with nickel and cobalt were found in meteorites (siderite) by early humans. This limited supply was used to shape tools and crude weapons. 

Cobalt is also found in seawater, meteorites, and other ores such as linnaeite, chloanthite, and smaltite, and traces are found mixed with the ores of silver, copper, nickel, zinc, and manganese. Cobalt ores are found in Canada and parts of Africa, but most of the cobalt used in the United States is recovered as a by-product of the mining, smelting, and refining of the ores of iron, nickel, lead, copper, and zinc. 

Nickel is the 23rd most abundant element found in the Earths crust. It is somewhat plentiful but scattered and makes up one-hundredth of 1% of igneous rocks. Nickel metal is found in meteorites (as are some other elements). It is believed that molten nickel, along with iron, makes up the central sphere that forms the core of the Earth. 

The dominant nuclear species resulting from processes at temperatures between 4 and 6 billion k include titanium-44, chromium-48, rron-52 and 53, nickel-56 and 57 and zinc-58, 60, 61 and 62. Isotopic abundances resulting from radioactive decay of these nuclei are compatible with terrestrial and meteoritic measurements relating to calcium-44, titanium-48, chromium-52 and 53, iron-56 and 57, and nickel-58, 60, 61 and 62. 

The abundance of nickel in the earth s crust is only 84 mg/kg, the 24 most abundant element. It is found in most meteorites, particularly in the iron meteorites or siderites, alloyed with iron. Its average concentration in seawater is 0.56 pg/mL. Nickel is one of the major components of the earth s core, comprising about 7%. 

Nickel is also found in meteorites and on the ocean floor in lumps of minerals known as sea floor nodules. The earth s core contains large amounts of nickel. Nickel is released into the atmosphere during nickel mining and by industries that make alloys or nickel compounds or industries that use nickel and its compounds. These industries may also discharge nickel in waste water. Nickel is also released into the atmosphere by oil-burning power plants, coalburning power plants, and trash incinerators. 

Nickel in Meteorites. Centuries before the discovery of nickel, primitive peoples shaped meteoric iron into implements and swords and appreciated the superiority of this Heaven-sent metal (125). In 1777 J. K. F. Meyer of Stettin noticed that when he added sulfuric acid to some native iron which P. S. Pallas had found in Siberia, he obtained a green solution which became blue when it was treated with ammonium hydroxide. In 1799 Joseph-Louis Proust detected nickel in meteoric iron from Peru (126). This grayish white native iron had been observed by Rubin de Celis. Since it did not rust, it was sometimes mistaken for native silver. 

Chromium in Meteorites. In 1817 Andre Laugier detected chromium and sulfur in the great Pallas meteorite from Siberia. Earlier analysts had reported only iron and nickel (91). 

Fischer-Tropsch synthesis over meteoritic iron, iron-ore and nickel-iron alloy. Geochim. Cosmochim. Acta, 40, 915-24. 

Early human civilizations used stone, bone, and wood for objects. Approximately ten thousand years ago, metals first appeared. The first metals used were those found in their native form, or in a pure, uncombined state. Most metals today are acquired from an ore containing the metal in combination with other elements such as oxygen. The existence of native metals is rare, and only a few metals exist in native form. Iron and nickel were available in limited supply from meteorites. The first metals utilized widely by humans were copper, silver, and gold. Pure nuggets of these metals were pounded, in a process known as cold hammering, with stones into various shapes used for weapons, jewelry, art, and various domestic implements. Eventually, smiths discovered if a metal was heated it could be shaped more easily. The heating process is known as annealing. Because the supply of native metals was limited, metal items symbolized wealth and status for those who possessed them. 

Among the elements that make up rocks and minerals, silicon, magnesium, and iron are of almost equal abundance followed by sulfur, aluminum, calcium, sodium, nickel, and chromium. Two of the most common minerals in meteorites and in the terrestrial planets are olivine ((Mg,Fe)2Si04) and pyroxene ((Mg,Fe,Ca)Si03). The composition obtained by averaging these two minerals is very similar to the bulk solar system composition, so it is really no surprise that they are so abundant. 

The amoeboid descriptor for amoeboid olivine aggregates refers to their irregular shapes. AOAs tend to be fine-grained and porous, and have comparable sizes to CAIs in the same meteorite. They consist mostly of forsterite and lesser amounts of iron-nickel metal, with a refractory component composed of anorthite, spinel, aluminum-rich diopside, and rarely melilite. The refractory component is sometimes recognizable as a CAI embedded within the AOA. The AOAs show no evidence of having been melted, but some contain CAIs that have melted. 

Mesosiderites are a highly enigmatic group of differentiated meteorites. They are breccias composed of iron-nickel metal and silicate in roughly equal proportions. The metal represents molten material from the deep interior of an asteroid, whereas the silicate fraction consists of basalts and pyroxene cumulates similar to HED meteorites that formed near the surface. It is difficult to construct models that allow mixing of such diverse materials, but these disparate materials are generally thought to have been violently mixed by impact. 

Metallic liquids can also experience fractional crystallization. The abundances of trace elements such as gold, gallium, germanium, and iridium and the major element nickel in various classes of iron meteorites vary because of the separation of crystalline metal phases (kamacite or taenite). 

---