Often, antique jewellery is described as ‘gold-cased’. The jewellery described as being gold-cased are Georgian and Victorian pieces such as seals, fobs, watches and small pendants. So what does the term mean? Gold-cased is another term for rolled gold, a long lasting form of plating. The process for rolled gold was invented in Birmingham in 1785 and was to be further developed in Birmingham over the next decades. It required a thick sheet of gold to be soldered to a thick sheet of brass. The ratio of the thickness of the two sheets would vary from 1:10 to 1:100. The double sheet was then rolled out to a thin sheet. The sheet lent itself to being punched and engraved and was very hard-wearing and durable. Sometimes the base used is of silver with the gold sheet placed on top. This is also called gold-cased.
Rolled gold or gold-cased is not the same as gold plate jewellery. Gold plating was invented in the 1840s and involved a process by which gold (or silver) was deposited on a metal base using electric current. It is a less durable process than rolled gold or gold casing, with a thinner coating of gold. Another plating process developed in the US was called ‘gold-filled’ and it involved a metal sheet being placed between two sheets of gold. It usually contains more gold than gold-cased or rolled gold items.
Trade description legislation required that a seller of jeweller must state if the item was made of rolled gold. Originally, the Commerce (Trade Descriptions ) Act 1905 (Cth), now significantly amended and applying to imported goods, contained the following definition in s 3:
“‘Rolled gold’ or ‘gold-cased’ means material consisting of a base metal covered by mechanical means with a shell or covering of gold of such quality and thickness as will effectively protect the underlying base metal from the action of pure nitric acid”.
‘Gold-plated’ and ‘gilt’ items had a different definition.
Rolled gold and gold-cased items can be stamped. Section 8 of the Australian Act mentioned above stated that the words ‘Rolled Gold’ or ‘Gold Cased’ should be ‘legibly stamped or engraved upon each article’.
Under the UK Hallmarking Act of 1973, rolled gold items cannot be hallmarked but can be stamped ‘gold plated’. Items which have silver as the underlying metal can be stamped with a silver hallmark (or 925 stamp on underweight articles) can be marked as follows ‘925 & 18ct gold plated’.
Generally, most antique gold-cased or rolled gold jewellery will not have stamped marks at all.