Question

Which color is given by cobalt oxides to glass?

Answer 1

Hint: Cobalt oxide is an inorganic compound having chemical formula \[Co_3O_4\]. It is a black colored antiferromagnetic solid.

Complete step by step answer:
-Color is the most obvious property of a glass object. It is one of the most interesting and beautiful properties. Color sometimes defines the usefulness of a glass object, but it almost always defines its desirability.
- In earlier times, people who were working with glass had no control over its color. Then, through certain experimentations, glass makers learned that adding certain substances to the molten glass would produce beautiful colors in the finished product. The main idea behind producing colored glass involves the addition of a metal (which imparts color) to the glass. This addition of metal is often achieved by adding some powdered oxide, sulfide, or other compound of that metal to the glass in the molten state.
Some of the coloring agents of glass are-
1.Cadmium sulfide imparts yellow color
2.Cobalt oxide imparts blue-violet color
3.Iron oxide imparts green color
4.Sulfur imparts yellowish-amber color
5.Copper compounds impart blue/green/red color
-There are certain decoloring agents as well. For example, Manganese Dioxide and Sodium Nitrate.These materials neutralize the coloring impact of impurities in the glass. Oxides of cobalt are often used as a blue coloring agent for pottery enamel and glass.

It imparts a deep blue color to the glass.

Additional information:
 Cobalt oxide is used as an electrode in some lithium-ion batteries in the form of nanoparticles of cobalt oxide. Cobalt compounds are potentially poisonous, when present in large amounts

Note:
Cobalt is required in our diet in trace amounts, i.e., $25mg$ on a daily basis. It is important for the functioning of cells at biological, chemical and molecular levels. Its deficiency may stimulate alternate pathways and cause diseases.