Multiple choice

The presence of which of the following substances imparts the deep blue colour to glass?

  1. Cupric oxide

  2. Iron oxide

  3. Cobalt oxide

  4. Nickel oxide
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Cobalt oxide is used as a coloring agent in glass manufacturing to produce deep blue glass. When added to the glass melt, cobalt ions create a stable blue coloration that has been used since ancient times. Other metal oxides like cupric oxide (blue-green), iron oxide (green/brown), and nickel oxide (brownish) produce different colors.

Keep practicing — related questions