May 5, 2016

Which is the most expensive substance in the list? A. Californium B. Cocaine C. Diamonds D. Plutonium A. Californium Going to Californium? Bring cash - this substance, a radioactive isotope, has many uses and runs a cool $27 million per gram. Cocaine costs a mere $215/gram; diamonds are a respectable $55,000/gram; and Plutonium, another radioactive isotope, is a mere $4,000 per gram.