Background | Name | Sources | Uses | Substitutes and Alternative Sources
Chromium is a hard, bluish metallic element (Cr) with an atomic number of 24. In the mid-1700’s, chemical analysis of a mineral from Siberia showed that it contained lead. This mineral, crocoite (PbCrO4, lead chromate), was known as “red lead” because of the beautiful orange-red color of its crystals. It also contained another, then-unknown material. This material was identified as chromium oxide (CrO3) by Louis-Nicholas Vauquelin. In 1797, he heated this oxide with charcoal to remove the oxygen (chemists call this reaction a reducing process) which left the metal chromium. Shortly after Vauquelin’s discovery, a German chemist name Tassaert discovered chromium in an ore that geologists now call chromite (FeCr2O4, ferrous chromic oxide). Chromite forms in an igneous environment.