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.
Iridium (one of the platinum group metals) is one of few metals that have a higher specific gravity than gold, being 22.6. Gold is around 8 times heavier than the quartz rock which it is commonly associated with when gold is found in hardrock form. A single cubic foot of gold will weigh approximately 1187 pounds. It is this quality of gold, having a superior weight factor over the other materials usually found along with it, that is used in most gold recovery methods. For example, watch in the following video segment how fast gold penetrates down through the lighter materials which commonly make up a streambed: