Sweden's Treskilling Yellow

Amey Stone on the Luxist.com website calls Sweden's Treskilling Yellow stamp (shown here) "the most expensive item in the world by weight and volume."

Probably the only one of its kind, it has a current value of more than $2 million -or $87 billion per kilogram.

According to Stone here's what makes it so valuable: Back in Sweden in 1855, when the currency was known as the skilling, the 3 skilling stamp ('treskilling') was printed in green. An 8 skilling stamp was printed in yellow. But due to a printing error, a few 3 skilling stamps were printed in yellow. No one knows how many.

Stone goes on to write, "Three years later, Sweden changed its currency and it wasn't until 1886 that a 14-year-old school boy discovered the stamp among his grandmother's possessions and sold it to a dealer for the then-lofty price of 7 kronor. The stamp traded hands several times over the next decade, fetching ever higher prices and inspiring collectors to search for more Treskilling Yellows. But no other was ever found."

By the 1990s the stamp price crossed $1 million for the first time and was setting records every time it changed hands. The last sale was in 1996 when it sold for 2,875,000 Swiss Francs ($2.6 million US) to collectors who remain anonymous. According to the book, The Treskilling Yellow, the stamp is insured for $15 million.

To learn more, click here.