From Chinese puzzle balls to Anglo-Indian furniture, tea caddies to letter openers, many antiques are comprised of elephant ivory. The European Union only allows the sale of antique ivory, from before 1947, but there has been no accurate way of distinguishing it from modern ivory. A scientist at Edinburgh Zoo, Dr Ross McEwing, said he has come up with a new test to determine the age of ivory by looking at its level of carbon isotope, which rose following nuclear testing in the 1950s.