The first element to be synthesised rather than being discovered in nature
Technetium was synthesised in 1937. Minute traces of technetium do occur naturally in the Earth's crustas a spontaneous fission product of 238U or by neutron capture in molybdenum ores. It is present in greater quantities naturally in red giant stars. The element is a remarkable corrosion inhibitor for steel, and is an excellent superconductor at 11K and below.