Fun Facts about Chromium

Chromium (Cr), the 24th element on the periodic table, is a hard, shiny, grey metal. It is also highly resistant to corrosion, making it useful in many applications. Several countries produce chromite ore, although South Africa is the most prolific producer. There are multiple ways to produce chromium including heating it with aluminum or charcoal and passing an electric current through chromium compounds. Four isotopes of chromium exist naturally, and seven radioisotopes have also been identified. These are sometimes used for medical research. Chromium has an interesting history, a wide variety of uses, and several known biological functions.

Fact 1: The identification and isolation of chromium were quite challenging.

A German mineralogist named Johann Gottlob Lehmann first characterized a mineral containing chromium in 1776. Scientists studying this mineral, which was called Siberian red lead, found that it had properties that could not easily be explained by the elements known at the time. A French chemist named Louis-Nicolas Vauquelin began to study this mineral in 1797 and determined that it contained a new metal. He was eventually able to isolate chromium during the following year.

Fact 2: Many chromium compounds are brightly colored.

The name chromium is derived from the Greek word for color, reflecting the fact that many chromium compounds are distinctively colored. They range from bright oranges and yellows to vivid greens and purples. Lead chromate, chromic oxide, and chromic sulfate are yellow and green pigments that are used in paint. Other chromium compounds are used to permanently integrate dyes into fabrics. Chromium salts can be used to dye leather, and chromium oxides added to glass make it green. The distinct colors of rubies and emeralds even come from chromium compounds.

Fact 3: Chromium and chromium compounds have many industrial applications.

Most chromium goes into alloys, mixtures of metal, to make them hard and corrosion resistant. It is frequently used in stainless steel, which is used from everything from kitchen appliances to trucks. Another common use for chromium is in refractory bricks, which reflect heat and are used to line ovens that reach very high temperatures. Finally, chromium can be used in electroplating, a process in which the chromium is applied in a very thin layer on top of another metal in order to make the surface corrosion resistant and shiny. Useful chromium compounds include chromium hexacarbonyl, which is a gas additive, and chromium boride, which is an electrical conductor that can withstand high temperatures.

Fact 4: Chromium plays direct roles in human metabolism

People require small amounts of chromium, which appears to regulate protein, fat, and carbohydrate metabolism. It also stimulates insulin activity, which means that future studies on chromium may provide insight into diabetes and how to best treat it. Whole grains, fruits, vegetables, meat, and even some spices contain chromium. While most people get enough chromium from food, a chromium deficiency can result in poor control of blood sugar levels and diabetes-like symptoms. Chromium is widely available as a supplement for those who need additional chromium in their diets such as the elderly or pregnant women.