Coins are a uniquely interesting form of durable art. About 3,000 years ago in Greece, people started using lumps of metal emblazoned with representations of authenticity for buying and selling, and they have evolved ever since then. Wikipedia defines a coin as “… a small, flat, round piece of metal used as a medium of exchange or legal tender. They are standardized in weight and produced in large quantities at a mint by a government in order to facilitate trade. Coins usually have images, numerals (date and value), and text (value, national mottos) on them. Obverse and reverse refer to the two flat faces of coins. In this usage, obverse means the front face of the object and reverse means the back face. The obverse of a coin is commonly called heads, because it often depicts the head of a prominent person, and the reverse tails.”