Another “most valuable ting” to this list. NO. 7. Plutonium: the average price of a gram per U.S. $ 4,000. NO. 15. Gold: price ranges per gram to about U.S. $ 56. “in between” NO. 6. and NO 7. there is another “most valuable thing”:

Jackson Pollock`s painting from 1948, New York. It weighs ca. 5000 gr. Canvas;costprice on the market 20.000.000 $ that is 4.000 $ pr. Gram.
You can see the painting here: http://www.youtube.com/watch?v=oUE9i-mHdPM

I can say, that this painting is on private hands with me in Copenhagen. It can be seen on ArtPrice, France Gallery.