A 14th level transmuter wizard has this feature:
Master Transmutation
Starting at 14th level, you can use your action to consume the reserve of transmutation magic stored within your transmuter’s stone in a single burst. When you do so, choose one of the following effects. Your transmuter’s stone is destroyed and can’t be remade until you finish a long rest.
(…)
- Restore Life. You cast the raise dead spell on a creature you touch with the transmuter’s stone, without expending a spell slot or needing to have the spell in your spellbook.
Raise dead (the cleric/paladin spell) has a costly material component:
A diamond worth 500gp
Does the wizard need the diamond to use his class feature?
Best Answer
As stated by Jeremy Crawford in this sage advice answer,
Since this feature doesn't specify that you don't need to provide components, you will by RAW have to not only provide the diamond, but also be able to provide Verbal and Somatic components to cast Raise Dead.