<P> At the Ancient Olympic Games only one winner per event was crowned with kotinos, an olive wreath made of wild olive leaves from a sacred tree near the temple of Zeus at Olympia . Aristophanes in Plutus makes a remark why victorious athletes are crowned with wreath made of wild olive instead of gold . Herodotus describes a story that explains why there were only a few Greek men at the Battle of Thermopylae since "all other men were participating in the Olympic Games" and that the prize for the winner was "an olive - wreath". When Tigranes, an Armenian general learned this, he uttered to his leader: "Good heavens! what kind of men are these against whom you have brought us to fight? Men who do not compete for possessions, but for honour". Hence medals were not awarded at the ancient Olympic Games . </P> <P> At the 1896 Summer Olympics, winners received a silver medal and the second - place finisher received a bronze medal . In 1900, most winners received cups or trophies instead of medals . The next three Olympics (1904, 1908, 1912) awarded the winners solid gold medals, but the medals themselves were smaller . The use of gold rapidly declined with the onset of the First World War and also with the onset of the Second World War . The last series of Olympic medals to be made of solid gold were awarded at the 1912 Olympic Games in Stockholm, Sweden . </P> <P> Olympic Gold medals are required to be made from at least 92.5% silver, and must contain a minimum of 6 grams of gold . All Olympic medals must be at least 60mm in diameter and 3mm thick . Minting the medals is the responsibility of the Olympic host . From 1928 through 1968 the design was always the same: the obverse showed a generic design by Florentine artist Giuseppe Cassioli of Greek goddess Nike with Rome's Colloseum in the background and text naming the host city; the reverse showed another generic design of Nike saluting an Olympic champion . </P> <P> From the 1972 Summer Olympics through 2000, Cassioli's design (or a slight modification) remained on the obverse with a custom design by the host city on the reverse . Noting that Cassioli's design showed a Roman amphitheater for what originally were Greek games, a new obverse design was commissioned for the 2004 Summer Olympics in Athens . For the 2008 Beijing Olympics medals had a diameter of 70mm and were 6mm thick, with the front displaying a winged figure of victory and the back showed a Beijing Olympics symbol surrounded by an inset jade circle . </P>

What are the olympic gold medals made of