Though the average specimen in captivity might live 25 or 35 years, an old koi named Hanako, from Mino province in Japan, has been shown to be over 215 years old based on analysis of her scales, and other 100+ year old fish are known from the same pond. Koi, like wild carp, can grow to 36 or more under perfect conditions.
The gold and silver medals weigh 412 grams (0.9 pounds) and the bronze medal weighs 357 grams (0.78 pounds). They are the biggest and heaviest summer Olympic medals ever made.
No medal is pure anything. The medals are a combination of gold, silver and copper to make it a harder alloy. Just like you would find in the coins we use every day in life. If you buy a gold bullion ounce today you will be paying close to $1,000 because of the market. Those coins may have an ounce of gold but it is not pure. The medals are no different; they do not have an ounce of gold it is normally around a quarter of an once