What's the difference between ruthenium and iridium spark plugs?

Spark plugs are made from many different materials. Ruthenium spark plugs are able to offer some different benefits from iridium and other plug types.
Dazebao News

Set Of 4 Iridium & Platinum Spark Plugs For Chevy Malibu, Cruze, Buick, GMC (2016-2020)

Promotion Acdelco Spark Plugs Set Of 4 Iridium & Platinum Spark Plugs For Chevy Malibu, Cruze, Buick, GMC (2016-2020) Chevy ...
Dazebao News

8 Ignition Coils & 16 Iridium Spark Plugs – Compatible With Jeep, Dodge, RAM 1500, Durango

Shop 2016 Ford Explorer Coil Pack 8 Ignition Coils & 16 Iridium Spark Plugs – Compatible With Jeep, Dodge, RAM 1500, Durango ...
Houston Chronicle

Platinum plugs should eliminate F-150's misfires

I have a 2002 Ford F150, 2WD, 4.6L V8, Auto Crew cab. At approximately 45,000 miles, I had several plug coils fail. The failed coils caused a considerable shake in the engine, occurring at all engine ...