The term Blue Glass refers to glass ware which has been made in Bristol, England since the 18th century. It is commonly known as Bristol Blue glass and it is uncertain when Bristol blue glass was first made. Blue Glass is believed to be first made in the 1700s. The quality and beauty of the glass quickly became popular, so that several glass houses had to be set up in the city. Cobalt oxide gives the deep and bright blue color to the glass. Chunks of glass is mixed with Cobalt Oxide and put into the furnace turned up to 1200°c and melted overnight. The glass melts and get mixed with the Cobalt Oxide forming the strong blue color. The glass makers of Bristol were invited to show their skills at the Great Exhibition of 1851, which was opened by Queen Victoria and Prince Albert. The production of Blue Glass had a break between the 1920s and 1980s. Now, Blue Glass is made by The Original Bristol Blue Glass Ltd in Brislington which was established in 1988. Blue Glass is available in the form of Bowls, Jugs, candle sticks, miniatures, plates, perfume bottles, jewellery etc. Most Blue glass seen today dates from late 19th century.