Osmium – $12.8 Million/Kg

Osmium is the densest of all the metals that occur naturally, and seeing as its uses are few and far between and that it’s extremely difficult to produce and handle in the naturally occurring state, the price tag on this element is ludicrous. It will cost you four hundred dollars per troy ounce which translates to roughly thirteen million dollars per kilogram.

The weird thing is, the price might rise even higher as time goes by. That’s because the alloys that are formed from this mineral have shown promising results in the medical field. Further tests need to be conducted, but so far, the data is looking good.