15 Of the Most Expensive Material Elements


2. Californium – $27 million per gram

Discovered in California in 1950, Californium is a rare earth metal that doesn’t occur naturally on the planet. Highly radioactive, one microgram of Californium releases up to 170 million neutron particles every minute, making it extremely toxic to most organic life. Uses of this element include detection of gold, platinum and moisture gauges for oil wells.