In antiques, the term cobalt blue is used to refer to cobalt blue glass or cobalt glass made by mixing cobalt oxide in a glass melt. Cobalt blue glass and glassware is bright deep blue colored. Cobalt blue glassware was seen produced in the post Civil War period. Cobalt blue dinner sets, bottles, pitchers, and other decorative items gained fame during the 1930s. We can see vintage and antique cobalt blue items which include decorative pieces, fruit bowls, pitchers, and bowls. Cobalt blue glasses are still being produced.