Question

Name the metal which is present as impurity in "sapphire".

Answer 1

Explanation for Correct answer:-

• Sapphire is a delicate gemstone made up of Aluminium-oxide and trace quantities of other elements including Copper($\mathrm{Cu}$), Magnesium($\mathrm{Mg}$), etc.
• Sapphire is also the impure form of Alumina(${\mathrm{Al}}_2{\mathrm{O}}_3$).
• Also, Sapphire contains Cobalt($\mathrm{Co}$) as an impurity.

Therefore, Cobalt($\mathrm{Co}$) is a metal that is present as an impurity in “sapphire”.