What is the importance of currency in the book, The Disappearing Spoon?

Currency, whether that be through coins or paper money, is one way in which the elements of the periodic table have played an important role in human culture, economics, and social structures. This connection is not unique to any particular human culture or single point in human history as the elements have played an important role in the development of currencies across time and space. The metallic elements such as gold, silver, and copper have traditionally played a significant role in coinage and in former economic systems such as the gold standard. Though most contemporary economies have switched to paper money, the elements still continue to play a role in some of those systems of currency, albeit in a new way. One example of this is in how europium is used as an anti-counterfeiting device on the Euro banknotes.