Chromium

Chromium is often alloyed with steel to harden it as stainless steel.   It provides a high-luster, non-corrosive metal plating to metal furniture frames and automobile trim.   It is a catalyst in some chemical reactions.   Chromium compounds are used in paint pigments, leather tanning, textile mordants, and aluminum anodizing. ^{Lide 4-8}   Chromite, the main ore of chromium, has a high melting point, low thermal expansion, and stable crystalline structure, so it is used for brick-making molds.

Chromium is essential to life.   It assists in the metabolism of glucose and in the proper functioning of motor and sensory nerves.   It helps reduce insulin and cholesterol levels.   Sources: meat, cheese, whole-grain breads and cereals.   In contrast, chromium compounds are toxic.

Chromium was discovered in 1797 by Louis Vauquelin, a French chemist.   The main ore for chromium is chromite, FeCr₂O₄, which is found in several foreign countries.   Chromium is obtained by reducing this oxide with aluminum or silicon.