Antimatter, $100 trillion per gram.

Antimatter is a material consisted of antiparticles. Mention of him is more often found in fiction literature. In the future, according to the scientists' forecasts, antimatter will be used for interplanetary flights. It takes the first place in value.

Californium-252, $27 million per gram.

The isotope of this chemical element is mainly used to detect water and oil in wells. It holds the second place in the world for the price.

Painite, $300,000 per gram, or $60,000 per karat.

Painite is the rarest mineral on Earth. Sometimes it is used for lithotherapy, that is, stone treatment. Takes the third place in value.

Diamonds.

Their price ranges from $65,000 per gram, or from $13,000 per karat. Real stones are expensive in every respect, but at a price are in the fourth place in the world among other expensive substances.

Tritium, $30,000 per gram.

Tritium is a luminescent substance. Most often it is used to highlight the tablets with the inscription "Exit" in public and private institutions. At the price, it occupies the fifth place.

Taaffeite, the price ranges from $2,500 to $20,000 per gram.

This is a precious gem of a lilac shade. It is very rare to find it - a million times less often than a diamond. Basically, taaffeite goes to jewelry. By value, it is in the sixth place in the world.

Plutonium, about $4,000 per gram.

This chemical element is radioactive. One type of plutonium is most often used for military purposes, the other for nuclear reactors.