Be cautious when bidding for items that are not fully described. Coins and medallions should state the size, composition and related year. Gold Filled means rolled gold. If it is stated "18k" ask for the country of manufacture (try and stand by British Assay marks) Some nefarious Chinese put "18k" on gold plated copper (I have been caught twice). There are reasons a seller will not give a full description of an item.Two items running at this time states "New antique ...........". How can you have a NEW antique.There are also some listings that state "24 carat Gold......"  Not in Britain there are not. 24 carat is Pure Gold and too soft for manufacturing purposes. The most common is the listings that have no description but the description box is filled with the sellers terms. Ask many questions

Addition. Some sellers often state "Hallmarked" and display a stamp on the item. This is sometimes the townmark especially continental Silver. A good investment is The Book of Old Silver by Seymour B Wylie. A hallmark in Britain, and sometimes former members of the British Empire. means the marks made by the assay office. Anchor for Birmingham, Leopards head for London, etc.this will be followed by a Lion Guardant for silver, or a Crown and number (9 or 18 for old gold or 375) in the same box. Then a letter mark to signify the year. On silver and gold items you will sometimes find the 'Duty Mark' of the sovereign or Britannia for pre-George 1 period.

(Added 01/08/2008) As a 'Retired Silversmith' I am quite astonished at the number of sellers that PERSIST in describing their item as "Hallmarked silver" when the item is merely stamped '925' This is NOT a Hallmark. A hallmark is the mark of the Goldsmiths Guild and the local Assay Office. It is a box containg a number relative to the content of Gold or silver called "The Milesmil mark" signifying the fineness of the metal in parts per thousand. This is contained with a box (or Oval) for Gold it is 375, 585,750, 916,990,999. For Silver it is 800, 925, 958, 999. For Platinum it is 850, 900, 950, 999. This is then followed by the Assay Office (in Britain) A leopard for London, An Anchor for Birmingham, A Rose for Sheffield, and a Castle for Edinburgh.

These silver Items Merely stamped '925' are made by the manufacturer and to pass them off as Silver, To describe the as Silver in the main is untrue. So if they do not carry a Hallmark and an Assay Office mark. DO NOT BID AS SILVER. It can be Fraud.