The Tiflis Stamp, also known as the Tiflis Unique, is one of the more interesting looking rare stamps in the world. With a metallic sheet and embossed lettering, it almost resembles a metal bookplate more than a stamp. It is one of the oldest surviving stamps from the Russian Empire, originating from the city of Tiflis (now part of the country of Georgia). Unlike most examples on this list, the Tiflis Stamp is not highly valued because of a misprint, but rather for the combination of its historical significance, aesthetic novelty, and rarity. There are only five of these stamps in existence