America joined World War II on the 8th of December, 1941, after the bombing of Pearl Harbour. To show solidarity with the war effort, a variety of patriotic jewels became popular. They frequently took the form of American flags (like this example) but could also feature jewelled representations of Uncle Sam or military figures.

Although the use of platinum in jewellery was outlawed by the American government during the war, in other respects the country’s jewellery trade prospered. Many stone dealers and cutters emigrated from Europe to America, taking their stock and expertise with them. As a result the United States, and the city of New York in particular, became an increasingly important centre for the gem and fine jewellery trade.