Gold, silver and bronze are what Olympic dreams are made of. However, the medals for the Olympic Games Rio 2016 have been made from extra special materials.

They’re a source of pride and joy when they’re draped around the neck of an athlete who’s trained for years to achieve their goal – they’re the medals of the Olympic Games.

But where do the medals come from? Produced by the Brazilian Mint, the 5 130 medals for the 2016 Olympic and Paralympic Games will be symbols of sustainability and accessibility as well as sporting excellence. The coveted prizes, which weigh 500g each, comprise 30 per cent recycled silver and bronze while the ribbons are made from 50 per cent recycled PET. Meanwhile, the gold medals are completely free of mercury.

The process of creating a single medal takes almost a full 48 hours, involves more than 100 operators, and nearly 16 steps.

But the creation of the 5 130 medals for the Olympic and Paralympic Games is heavily guarded in secrecy.

“We had the whole project, the whole design, the whole material, everything here, but we can’t take pictures, or tell anyone,” said Victor Berbert, manager of metals at the Brazilian Mint.

For two years before the games, designers took the medal from the concept to the real thing.

First in the process, artists sculpted the goddess Nike with other details. Then, operators use that sculpture to create the mould. Once the mould is created, the medal can be cast into what top Olympians wear on the podium. Last up are the finer details – inscribing the name of every event into every medal.

The Olympic medal design includes the traditional laurel leaf while the Paralympic prizes feature engravings representing the “seeds of courage, persistence and development of the athletes.” As is tradition, the reverse side of the medal displays an etching of Nike, the Greek goddess of victory.

The gold medals are purer than ever, meeting sustainability criteria from extraction to refining, as well as meeting strict environmental and labour laws. They make use of recycled raw silver at 92.5 per cent purity, coming from leftover mirrors, waste solders and X-ray plates. And 40 per cent of the copper used in the bronze medals came from waste at the Mint itself.

The Olympic gold medal is instead made of silver and only plated with gold, or to be more precise: 494 grams of silver (92.5 per cent) and 6 grams of gold.

The medals are created using a special mould at the Brazilian mint. This could have been made using a computer but for the Rio medals, sculptor Nelson Neto Carneiro crafted them himself over a two week period by hand to give him more control over the design.

The completed mould was then scanned into the computer and a cutting machine used to turn it into a metallic mould, with a microscope used for quality control.

Once finished, a press machine hit the mould. The Gold medals were then placed in a ‘bath of gold’ to cover them.

Olympic gold medals are arguably priceless in value, but the melted down value of a gold medal would be around £450 ($587). Silver medals meanwhile contain 500 grams of silver and melted down would hold a value of around £236 ($305).

However, the melted down value of the bronze medal would only be £2-£3 as it is made up of 475 grams of copper (95 per cent) and 25 grams of zinc (5 per cent). Brass rather than bronze is used as bronze would corrode over time and become green.

Finally, the medals were packed up and shipped off to the Games, where medal creators got to see their finest work on display for the world to see.

“It was truly amazing to do that. When we see the complete and finished medals on the chests of the athletes, it’s amazing, fantastic for us.”

Why do athletes bite their gold medals?
Historically, people bite down on gold to check if it is real. Solid gold should be soft enough to leave teeth marks – whereas cheap knock-offs won’t. So given that the Olympic medals aren’t made of gold, biting the medal might seem a little pointless.

However, in recent years biting the medal has become a bit of a tradition so photographers will ask winners to pose with the medal between their teeth to get an alternative shot.

Were gold medals ever made of pure gold?
Yes, solid gold was used at games including and prior to the 1912 Summer Olympic games in Stockholm, Sweden.