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?