Chromium compounds are used as pigments in paints and by the leather industry for the chrome tanning of hides. The textile dyeing industry uses chromium as mordants, or fixatives, to improve the brilliance and fastness of certain dyestuffs.
Chromium forms two series of salts, called chromium (I), or chromous, and chromium (II), or chromic. It also forms chromates (VI), containing the ion CrO42-. Its most common isotope is 52Cr.
Chromium, which is not found free in nature, was first obtained in 1798 by the French chemist Louis-Nicholas Vauquelin by heating (and thereby reducing) the ore crocite (PbCrO4, lead chromate). Shortly after Vauquelin's discovery, a German chemist named Tassaert discovered chromium in the ore chromite.
The name "chromium" comes from the Greek chroma meaning "color", in reference to the fact that chromium results in the distinctive coloration of a variety of materials. For example, the green color of emerald is caused by the presence of very small amounts of chromium in the crystal.
Related category INORGANIC CHEMISTRY
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