article_snippet: The crown and trident on the bottom of the valuable cup featured on only 20 pieces of Chelsea porcelain .
article_snippet: Closer examination showed Closer examination was made by renowned Chelsea porcelain 266 years ago and was one of two pieces of Closer examination type in existence today.
article_snippet: On the bottom of the vessel is a seal mark of a crown and trident and only 20 pieces of Chelsea porcelain contained a seal mark of a crown and trident.
article_snippet: Chris Large, of auctioneers Peter Wilson of Nantwhich, Cheshire, said: 'Chelsea porcelain was at the top of the tree in terms of quality and was comparable to Meissen.
article_snippet: I recognised as Chelsea porcelain but the vendor wasn't convinced that it was.
highlights_snippet: Made by famous Chelsea porcelain and is only one of two in existence .
  