Platinum
Characteristics
Characteristics
---------------

### Physical

Pure platinum is a lustrous, [ductile](/wiki/Ductility "Ductility"), and [malleable](/wiki/Malleable "Malleable"), silver\-white metal. Platinum is more ductile than [gold](/wiki/Gold "Gold"), [silver](/wiki/Silver "Silver") or [copper](/wiki/Copper "Copper"), thus being the most ductile of pure metals, but it is less malleable than gold.

Its physical characteristics and chemical stability make it useful for industrial applications. Its resistance to wear and tarnish is well suited to use in fine [jewellery](/wiki/Jewellery "Jewellery").

### Chemical

[thumb\| upright\=1\.3\|left\|Platinum being dissolved in hot *[aqua regia](/wiki/Aqua_regia "Aqua regia")*](/wiki/File:Platin_l%C3%B6st_sich_in_hei%C3%9Fem_K%C3%B6nigswasser.jpg "Platin löst sich in heißem Königswasser.jpg")

Platinum has excellent resistance to [corrosion](/wiki/Corrosion "Corrosion"). Bulk platinum does not oxidize in air at any temperature, but it forms a thin surface film of [](/wiki/Platinum_dioxide "Platinum dioxide") that can be easily removed by heating to about 400 °C.

The most common [oxidation states](/wiki/Oxidation_state "Oxidation state") of platinum are \+2 and \+4\. The \+1 and \+3 oxidation states are less common, and are often stabilized by metal bonding in bimetallic (or polymetallic) species. Tetracoordinate platinum(II) compounds tend to adopt 16\-electron [square planar](/wiki/Square_planar "Square planar") geometries. Although elemental platinum is generally unreactive, it is attacked by [chlorine](/wiki/Chlorine "Chlorine"), [bromine](/wiki/Bromine "Bromine"), [iodine](/wiki/Iodine "Iodine"), and [sulfur](/wiki/Sulfur "Sulfur"). It reacts vigorously with fluorine at  to form [platinum tetrafluoride](/wiki/Platinum_tetrafluoride "Platinum tetrafluoride"). Platinum is insoluble in [hydrochloric](/wiki/Hydrochloric_acid "Hydrochloric acid") and [nitric acid](/wiki/Nitric_acid "Nitric acid"), but dissolves in hot *[aqua regia](/wiki/Aqua_regia "Aqua regia")* (a mixture of nitric and hydrochloric acids), to form aqueous [chloroplatinic acid](/wiki/Chloroplatinic_acid "Chloroplatinic acid"), :

 
As a [soft acid](/wiki/HSAB_theory "HSAB theory"), the  ion has a great affinity for sulfide and sulfur ligands. Numerous DMSO complexes have been reported and care is taken in the choosing of reaction solvents.

In 2007, the German scientist [Gerhard Ertl](/wiki/Gerhard_Ertl "Gerhard Ertl") won the [Nobel Prize in Chemistry](/wiki/Nobel_Prize_in_Chemistry "Nobel Prize in Chemistry") for determining the detailed molecular mechanisms of the catalytic oxidation of [carbon monoxide](/wiki/Carbon_monoxide "Carbon monoxide") over platinum ([catalytic converter](/wiki/Catalytic_converter "Catalytic converter")).

### Isotopes

Platinum has six naturally occurring [isotopes](/wiki/Isotopes "Isotopes"): , , , , , and . The most [abundant](/wiki/Isotopic_abundance "Isotopic abundance") of these is , comprising 33\.83% of all platinum. It is the only stable isotope with a non\-zero [spin](/wiki/Spin_%28physics%29 "Spin (physics)"). The spin of 1/2 and other favourable magnetic properties of the nucleus are utilised in [ NMR](/wiki/Platinum-195_nuclear_magnetic_resonance "Platinum-195 nuclear magnetic resonance"). Due to its spin and large abundance,  satellite peaks are also often observed in  and  NMR spectroscopy (*e.g.,* for Pt\-phosphine and Pt\-alkyl complexes).  is the least abundant at only 0\.01%. Of the naturally occurring isotopes, only  is unstable, though it decays with a half\-life of 6\.5 years, causing an activity of 15 [Bq](/wiki/Becquerel "Becquerel")/kg of natural platinum. Other isotopes can undergo [alpha decay](/wiki/Alpha_decay "Alpha decay"), but their decay has never been observed, therefore they are considered stable. Platinum also has 38 synthetic isotopes ranging in atomic mass from 165 to 208, making the total number of known isotopes 44\. The least stable of these are  and , with half\-lives of 260 μs, whereas the most stable is  with a half\-life of 50 years. Most platinum isotopes decay by some combination of [beta decay](/wiki/Beta_decay "Beta decay") and alpha decay. , , and  decay primarily by [electron capture](/wiki/Electron_capture "Electron capture").  and  are predicted to have energetically favorable [double beta decay](/wiki/Double_beta_decay "Double beta decay") paths.

### Occurrence

[thumb\|left\|A native platinum nugget, [Kondyor](/wiki/Kondyor_Massif "Kondyor Massif") mine, [Khabarovsk Krai](/wiki/Khabarovsk_Krai "Khabarovsk Krai")](/wiki/File:Platinum-nugget.jpg "Platinum-nugget.jpg")
[thumb\|left\|Platinum\-palladium ore, Stillwater mine, Beartooth Mountains, Montana, US](/wiki/File:Platinum-palladium_ore%2C_Stillwater_mine_MT.JPG "Platinum-palladium ore, Stillwater mine MT.JPG")
[thumb\|left\|Sulfidic serpentintite (platinum\-palladium ore) from Stillwater Mine, Beartooth Mountains, Montana, USA](/wiki/File:Sulfidic_serpentintite_%28platinum-palladium_ore%29_Johns-Manville_Reef%2C_Stillwater_Complex.jpg "Sulfidic serpentintite (platinum-palladium ore) Johns-Manville Reef, Stillwater Complex.jpg")
Platinum is an extremely rare metal, occurring at a concentration of only 0\.005 [ppm](/wiki/Parts_per_million "Parts per million") in [Earth's crust](/wiki/Earth%27s_crust "Earth's crust"). Sometimes mistaken for silver, platinum is often found chemically uncombined as native platinum and as [alloy](/wiki/Alloy "Alloy") with the other platinum\-group metals and [iron](/wiki/Iron "Iron") mostly. Most often the native platinum is found in secondary deposits in [alluvial](/wiki/Alluvium "Alluvium") deposits. The alluvial deposits used by [pre\-Columbian](/wiki/Pre-Columbian "Pre-Columbian") people in the [Chocó Department](/wiki/Choc%C3%B3_Department "Chocó Department"), [Colombia](/wiki/Colombia "Colombia") are still a source for platinum\-group metals. Another large alluvial deposit is in the [Ural Mountains](/wiki/Ural_Mountains "Ural Mountains"), Russia, and it is still mined.

In [nickel](/wiki/Nickel "Nickel") and [copper](/wiki/Copper "Copper") deposits, platinum\-group metals occur as [sulfides](/wiki/Sulfide "Sulfide") (e.g., , [tellurides](/wiki/Telluride_%28chemistry%29 "Telluride (chemistry)") (e.g., ), [antimonides](/wiki/Antimonide "Antimonide") (PdSb), and [arsenides](/wiki/Arsenide "Arsenide") (e.g. ), and as end alloys with nickel or copper. Platinum arsenide, [sperrylite](/wiki/Sperrylite "Sperrylite") (), is a major source of platinum associated with nickel ores in the [Sudbury Basin](/wiki/Sudbury_Basin "Sudbury Basin") deposit in [Ontario](/wiki/Ontario "Ontario"), [Canada](/wiki/Canada "Canada"). At [Platinum, Alaska](/wiki/Platinum%2C_Alaska "Platinum, Alaska"), about  was mined between 1927 and 1975\. The mine ceased operations in 1990\. The rare [sulfide mineral](/wiki/Sulfide_mineral "Sulfide mineral") [cooperite](/wiki/Cooperite_%28mineral%29 "Cooperite (mineral)"), , contains platinum along with [palladium](/wiki/Palladium "Palladium") and nickel. Cooperite occurs in the [Merensky Reef](/wiki/Merensky_Reef "Merensky Reef") within the [Bushveld complex](/wiki/Bushveld_complex "Bushveld complex"), [Gauteng](/wiki/Gauteng "Gauteng"), [South Africa](/wiki/South_Africa "South Africa").

In 1865, [chromites](/wiki/Chromite "Chromite") were identified in the Bushveld region of South Africa, followed by the discovery of platinum in 1906\.Dan Oancea [Platinum In South Africa](http://www.infomine.com/publications/docs/Mining.com/Sep2008e.pdf) . MINING.com. September 2008 In 1924, the geologist [Hans Merensky](/wiki/Hans_Merensky "Hans Merensky") discovered a large supply of platinum in the [Bushveld Igneous Complex](/wiki/Bushveld_Igneous_Complex "Bushveld Igneous Complex") in South Africa. The specific layer he found, named the [Merensky Reef](/wiki/Merensky_Reef "Merensky Reef"), contains around 75% of the world's known platinum. The large copper–nickel deposits near [Norilsk](/wiki/Norilsk%23Norilsk-Talnakh_nickel_deposits "Norilsk#Norilsk-Talnakh nickel deposits") in [Russia](/wiki/Russia "Russia"), and the [Sudbury Basin](/wiki/Sudbury_Basin "Sudbury Basin"), [Canada](/wiki/Canada "Canada"), are the two other large deposits. In the Sudbury Basin, the huge quantities of nickel ore processed make up for the fact platinum is present as only 0\.5 [ppm](/wiki/Parts_per_million "Parts per million") in the ore. Smaller reserves can be found in the United States, for example in the [Absaroka Range](/wiki/Absaroka_Range "Absaroka Range") in [Montana](/wiki/Montana "Montana"). In 2010, South Africa was the top producer of platinum, with an almost 77% share, followed by Russia at 13%; world production in 2010 was .

Large platinum deposits are present in the state of [Tamil Nadu](/wiki/Tamil_Nadu "Tamil Nadu"), [India](/wiki/India "India").

Platinum exists in higher abundances on the [Moon](/wiki/Moon "Moon") and in meteorites. Correspondingly, platinum is found in slightly higher abundances at sites of [bolide](/wiki/Bolide "Bolide") impact on Earth that are associated with resulting post\-impact volcanism, and can be mined economically; the [Sudbury Basin](/wiki/Sudbury_Basin "Sudbury Basin") is one such example.


Are there any other minerals besides palladium and nickel present in cooperite?