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Cobalt is a chemical element; it has symbol Co and atomic number 27. As with nickel, cobalt is found in the Earth's crust only in a chemically combined form, save for small deposits found in alloys of natural meteoric iron. The free element, produced by reductive smelting, is a hard, lustrous, somewhat brittle, gray metal.
[5] [6] Various amalgams of silver and mercury or other metals and mercury do occur rarely as minerals in nature. An example is the mineral eugenite (Ag 11 Hg 2) and related forms. [7] Silver nuggets, wires, and grains are relatively common, but there are also a large number of silver compound minerals owing to silver being more reactive than gold.
Abundance (atom fraction) of the chemical elements in Earth's upper continental crust as a function of atomic number; [5] siderophiles shown in yellow Graphs of abundance against atomic number can reveal patterns relating abundance to stellar nucleosynthesis and geochemistry.
The abundance of the chemical elements is a measure of the occurrences of the chemical elements relative to all other elements in a given environment. Abundance is measured in one of three ways: by mass fraction (in commercial contexts often called weight fraction), by mole fraction (fraction of atoms by numerical count, or sometimes fraction of molecules in gases), or by volume fraction.
Cobalt is toxic to touch and breathe in, and can be found alongside traces of radioactive uranium. Cancers, respiratory illnesses, miscarriages, headaches and painful skin conditions occur among ...
Heterogenite has an average grade of 64.1% cobalt, one of the highest rates among cobalt-containing minerals. [7]Similar to most oxyhydroxides, heterogenite acts as a chemical 'sponge', trapping many trace elements such as Ni, Zn, V, As, Mo, and Pb.
Naturally occurring cobalt, Co, consists of a single stable isotope, 59 Co (thus, cobalt is a mononuclidic element). Twenty-eight radioisotopes have been characterized; the most stable are 60 Co with a half-life of 5.2714 years, 57 Co (271.811 days), 56 Co (77.236 days), and 58 Co (70.844 days). All other isotopes have half-lives of less than ...
One, in the journal Nature Astronomy, found that the samples contained a diverse mixture of organic compounds. And the other, in the journal Nature, found that the samples contained minerals ...