Failed spell with expensive component

[Raezeman]

Let's say, you try to cast true resurrection to bring back a buddy, but the spell failed, because for example he wasn't actually dead (his death was staged for example). Would the 25000 gp worth diamonds be used up in this failed attempt, or would it only be used up when true resurrection is cast successfully?

[PraxisVetli]

It sucks, but yes. Because techincally, the spell didnt fail, it was just ineffective. So since you did cast, the component is used.
Like Nat 1ing while true strike'd

[Zubrowka74]

And if the spell is interrupted you keep them ?

[Curmudgeon]

And if the spell is interrupted you keep them ?
It depends how the spell was interrupted. If it's interrupted by counterspelling the casting is far enough along that everything is wasted. If it's interrupted by damage or some other distraction during the casting and you fail the Concentration check to continue, again everything is wasted. If it's interrupted by an immediate action, the spell is actually preempted so no casting took place and all your stuff is intact.