Trust But Verify

A photo-op we see over and over at the Olympics is the Gold Medal Winner biting the medal, an apparent reference to the old time practice of biting a gold coin to verify that it's made of true gold:

Aly Raisman - US Gymnastics

Of course, Olympic Gold Medals are not pure gold.  Olympic Gold medal are actually 92.5% silver, plated with 6 grams of 24 karat gold.  Since silver is slightly harder than gold, and most alloys are harder than the pure metal, these girls are risking dental damage.

Jaime Gray - US Rifle

 More Olympic chicks biting their medals below.  They guys do it too, but who cares?

Jessica Ennis - UK Heptathlon

Jessica Rossi - Italy Trap Shooting

Kayla Harrison - US Judo

Kim Jang-Mi - South Korea Pistol

Roosannagh MacLennan - Canada Trampoline

Wenjun Guo - China Air Pistol

Yana Shenyakin - Ukraine Fencing

Ruta Meilutyte - Lithuania Swimming

Serena Williams - US Tennis

An Kum Ae - North Korea Judo

This last one looks like she might really want to eat it.

North Korea's key to success: Fridges for winners, labour camps for losers

Italian Fencing Team

Elisa Di Francisca, Arianna Errigo, Valentina Vezzali and Ilaria Salvatori