synthetic element

synthetic element (plural synthetic elements)

1. A chemical element that does not occur naturally (on Earth) and must be synthesized (manufactured).

   Synonym: artificial element

• May or may not include elements that occur naturally on Earth, but in such small amounts that they are, for most practical purposes, synthetic: technetium, promethium, astatine, francium, neptunium, and plutonium. Also, actinides up to and including at least einsteinium have been detected in Przybylski's Star.

• synthetic element on Wikipedia.Wikipedia