Transition metals are responsible for the colours of most gemstones


Transition metal index


Geometries of complexes


Crystal field theory




Transition Metals


Transition metals form very colorful compounds. Unlike the compounds made with the metals in groups 1 and 2 of the periodic table (like Na or Mg) which are usualy grey or white, transition metals display lots of different colours. Again, this special property of transition metals is a consequence of having d orbitals.

The colours will depend not only on the metal but also on its oxidation state and on the ligands attached to it .

Familiar colours produced by transition metals include the deep purple potassium permanganate solution (caused by Mn7+), the blue copper sulfate solution (caused by Cu2+) and the red colour of blood, soil, kidney beans and rust (caused by Fe3+).

Red rocks (containing Fe3+) at the Pirineo Mountains beteen France and Spain and on the right the sign describing the red desert (desert rouge)




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