RMS Queen Mary Propeller Ashtray

• Manganese Glaze - A manganese glaze contains manganese dioxide as a colorant. When fired at high temperatures, the manganese dioxide in the glaze reacts with the clay body to create a range of colors, including brown, black, purple, and deep red.
  
  Manganese glazes have been used to decorate ceramics for thousands of years, and they have been particularly popular in Chinese and Korean pottery. In China, manganese glazes were first used during the Song dynasty (960-1279 AD), and they were later used in the production of Jun ware during the Ming dynasty (1368-1644 AD). In Korea, manganese glazes were used to decorate celadon pottery during the Goryeo dynasty (918-1392 AD).
  
  The glaze can be applied to pottery using a variety of techniques, including brushing, pouring, and spraying. The glaze can be applied alone or in combination with other glazes to create a range of effects, including speckled or mottled surfaces. However these glazes can be difficult to control, as they tend to be very fluid and can easily run or drip during firing. However, this fluidity can also be used to create interesting effects, such as the "hare's fur" pattern that is often seen in Chinese tea bowls.
  
  Manganese glazes are still in use by potters and ceramic artists to create unique and beautiful surfaces on their work.
• Bronze - An alloy of copper and tin, traditionally in the proportions of about 9 parts of copper to 1 part of tin.
  
  The discovery of bronze in Western Asia in the 4th century enabled people to create metal objects which were superior to those previoulsy possible because of its strength and hardness, and it has been used throughout the world for weapons, coins, tools, statuary and other decorative items.
  
  It is very fluid in a molten state, and its hardness, strength when set, and non-corrosive properties makes it most suitable for casting sculpture.

This item has been included into following indexes:

• cruise liner and shipping - memorabilia 92