Lunar chemistry

The European Space Agency's D-CIXS detected the major components of rocks: aluminum, silicon, magnesium, and calcium. However, elements like calcium are not homogenously mixed throughout the Moon.

Non-natural elements
A significant amount of Uranium 236 and Neptunium 237 was confirmed on the Moon in 2009, but was known about as early as 1972. Uranium 236 is a radioactive nuclear waste which is found in spent nuclear and reprocessed Uranium. Neptunium 237 is a radioactive metallic element and a by-product of nuclear reactors and the production of Plutonium. These elements have never been found to occur naturally.