Armed Forces Brooches: Royal Navy and Australian Military

• Rolled Gold - A type of gold plating devloped in the early 19th century, similar to Sheffield plating of silver, where the the gold is fused under pressure and heat to a base metal, usually brass, and then rolled into sheets of the required thickness.
  
  The thickness of the gold plate can vary. In Britain the thickness of the gold is measured in microns. A micron is one-thousandth of a millimetre and 20 microns of gold is considered good quality. In the USA a differnt method is used that takes account of the total weight of the object.
  
  Also, the purity of the gold, measured in carats can vary, with 24 carat being the purest. The gold in most rolled gold objects will be between 9 and 14 carats.
  
  There are other chemical and electroplating methods of applying gold plate to a base metal, but rolled gold is considered a superior plate to a "gold plated" object.
  
  Depending on the country and date of manufacture, the object may be stamped "Rolled Gold" or similar, but if there is any doubt as to whether an object is solid gold, or some type of gold plating, it is preferable to have it tested by a jeweller.
• Sterling Silver - Sterling silver is a mixture of 92.5% pure silver and 7.5% of another metal, usually copper. Fine silver is 99.9% pure silver, and is relatively soft and the addition of the very small amount of copper gives the metal enough strength and hardness to be worked into jewellery, decorative and household objects.

This item has been included into following indexes:

• brooches, gold - gold, no gemstones 1,581
• brooches, silver - silver items 2,539