Could a Kineticist with Metal Blast that's been modified with Rare-Metal Infusion use his infused blast to trigger one of the special effects with the Weapon Material Mastery feat?
Weapon Material Mastery: 'While wielding an appropriate melee weapon,'
Rare-metal Infusion: 'You can control the properties of metal, allowing your metal blast to bypass damage reduction as if it were adamantine, cold iron, or silver (your choice).'
I'm not sure that 'as if it were' is the same as an appropriate melee weapon.
If it does work you need primary element earth, expanded element earth, rare-metal infusion & kinetic blade, and you need to be able to pay a base cost of 5 burn. Also you'll need base attack +7 and either weapon training or the Martial Focus feat. It sounds late-game enough that I'd allow it considering what else is flying around by then, but I don't think it works RAW.