I usually have no trouble recognising and using English or Australian hallmarks on antique jewellery to date the piece but have a lot of difficulty deciphering French hallmarks. In this post, I am only talking about silver marks but that is complicated enough.
France has had a long history of assay and other marks but the French Revolution led to a consolidation of hallmarks. By 1838, a simpler system of marks to guarantee the purity of a piece of silver was introduced.
The first component of French hallmarks is the purity standard or guarantee. The silver standard for jewellery around the world has varied throughout history. We are used to knowing that .925 stamped on a piece of white metal jewellery means that the item is made of 92.5% silver, described as sterling silver. But other countries use different standards. France currently accepts two silver standards, .950 and .800.
The silver guarantee stamp on French silver differs depending on the size of the item. Smaller items will have a boar’s head, a crab or a head of Minerva without a frame. Larger items will have a head of Minerva with a frame. The shape of the frame around the head will vary depending on whether the item is made of 950% silver or 800%. If the item was made for export, the head of Mercury is used.
The most common mark on jewellery is the boar’s head, the mark of the Paris Assay Office, indicating a fineness of 800 or higher. This mark has been used from 1838 to 1961. Outside of Paris, the crab mark was used from 1838 to 1961, and since 1962, has also been used by the Paris Assay Office.
The second mark on a silver item is a maker’s mark. Since 1797, marker’s marks are contained in a diamond lozenge shape. From 1838, the maker’s mark and the silver guarantee mark, for instance, the boar’s head, are the only marks that will be on the item.
Dating French jewellery is difficult because the boar’s head for silver (and other guarantee stamps like the eagle’s head for gold or the dog’s head for platinum) have been used since 1838 until 1961 and they don’t use date letters. The two stamps (the guarantee mark and the maker’s mark) on a piece tell you that it was made after 1838 and that it is silver. To determine the age of a piece, though, it is necessary then to recognise the style and the era in which that style was made and worn.
The last point I want to make about French silver marks is that they are often very difficult to see. Some of them look just like an irregular rough surface on the silver back rather than a stamp. Also, the boar’s head and the maker’s mark may be quite separately placed on the piece of silver.