While it is the rarest stable isotope of Mercury, at a proportion lower than that of 235 U in natural uranium, Hg-196 is of some theoretical interest in the synthesis of precious metals via nuclear transmutation since it could - in theory - be transmutated into the only stable gold isotope 197 Au via neutron absorption and subsequent decay via electron capture. However, given that a costly step of isotope separation would have to precede the already costly process of transmutation, this has (as of 2022) mostly remained a theoretical curiosity rather than an actual area of research.