cobalt

Name cobalt
Symbol Co
Atomic Weight 58.933200
Atomic Number 27
CAS ID 7440-48-4
Group Number 9
Group Name (none)
Period Number 4
Origin of Name German, koblad = "goblin."
Year Discovered 1735
Discovery Credits Discovered by G. Brandt at Stockholm, Sweden.
Class Metallic
Color Lustrous, metallic, grayish tinge
Standard State Solid at 77 F & 298 K
Description Lustrous, silvery-blue, hard mental; ferromagnetic. Stable in air, slowly attacked by dilute acids. Cobalt 60 is a useful radio isotope. Used in alloys for magnets, ceramics, catalysts, and paints.

Diagnostic tests: 
A beautiful blue bead is obtained with using the borax bead test in the oxidizing and reducing flame. If sulfur or arsenic is present, the mineral should be roasted first to oxidize those elements.
A magnetic mass is obtained if the mineral is powdered, mixed with soda (Na2CO3), and fused in a reducing flame (Note, Iron and Nickel are also yield magnetic masses).
In solution, cobalt forms pink to red to blue solutions, yielding a bluish pink precipitate (Co2+(OH)2) on adding NaOH. H2O2 will turn the precipitate black (Co3+(OH)3).

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