How Much Uranium is there on Earth?

On Earth surface, the average density of Uranium is 3.10% which is actually a lot comparing to other elements. The density is 30 times of silver and 1000 times of gold. Quantity of Uranium in granite is also enough, which is almost 25gm per tonn. Sea water also contains good amoumt of Uranium- almost 3.4 microgram per litre.

The amount of Uranium in the outer 20Km thick surface of Earth is almost 10^14 tonn. Uranium is one those matters which are scattered all around the world. A very small amount of it can be found in minerals. But amount there is not more than 0.3%.