Crystalline Solid Crystalloid Curie Curium Cyclic Compound Cyclohexane Cyclotron Chromium , symbol Cr, gray metallic element that can take on a high polish. Chromium can replace part of the aluminum or iron in many mineral s, imparting to them their unique colors. Many precious stones owe their color to the presence of chromium compounds. Most of these compounds are green, but some are red or blue.
Chrome green is a mixture of chrome yellow and Prussian blue.
USES More than half the production of chromium goes into metallic products, and about another third is used in refractories. It is an ingredient in several important catalyst s. The chief use of chromium is to form alloy s with iron, nickel , or cobalt . The addition of chromium imparts hardness, strength, and corrosion resistance to the alloy. In the stainless steels, chromium makes up 10 percent or more of the final composition.