spe·cial

– adj.
1. of a distinct or particular kind or character.
2. being a particular one; particular, individual, or certain.
3. pertaining or peculiar to a particular person, thing, instance, etc.; distinctive; unique.
4. having a specific or particular function, purpose, etc.
5. distinguished or different from what is ordinary or usual.
6. extraordinary; exceptional, as in amount or degree.
7. being such in an exceptional degree; particularly valued.

rare

– adj.
1. coming or occurring far apart in time; unusual; uncommon.
2. thinly distributed over an area; few and widely separated.
3. having the component parts not closely compacted together; not dense.
4. unusually great.
5. unusually excellent; admirable; fine.

u·nique

– adj.
1. existing as the only one or as the sole example; single; solitary in type or characteristics.
2. having no like or equal; unparalleled; incomparable.
3. limited in occurrence to a given class, situation, or area.
4. limited to a single outcome or result; without alternative possibilities.
5. not typical; unusual.