Cesium
This liquid metal is highly prized for use in electrical
components, and as a catalytic agent.
Lythia
This extremely absorbent synthetic element has become
indispensable when it comes to cleaning up nasty industrial messes.
Iridium
Like Rhodium, Iridium does all sorts of neat things
when combined with Platinum. In addition, it has a large variety
of industrial applications all by itself. A very handy mineral to
keep around.
Platinum
Tough, resilient and highly conductive, Platinum
has become one of the most important mineral resources on all industrialized
planets.
Rhodium
Wherever people need Platinum, they also need Rhodium. These elements go together like ice cream and fudge sauce (although they're a good deal more toxic).