Not silver, lead. Silver is not practical.
https://bullion.directory/cern-scientists-create-230m-dollars-gold-in-lab/
Inside a neutron star or during a supernova; because what you are describing is actually nuclear fusion. You want to do it anywhere else you need something that is very similar with a higher atomic number, like lead. Using fission it is easily possible to knock protons off of an atom to turn it into a lower number, so making lead into gold, platinum, etc is possible although impractical.
apparently also from neutron star collisions.