- RARITY
- A flying pig, e.g.
- Blue moon, e.g.
- It's not seen that often
- Quality prized by numismatists
- Unusual find
- Hole in one, e.g.
- One for the books
- Antiquarian's find
- Highly unusual occurrence
- It happens once in a blue moon
- Unlikely occurrence
- Triple play, e.g.
- It doesn't happen often
- Albino, for one
- It's unlikely
- Uncommon thing
- Event associated with a blue moon
- Something you don't see everyday
- Uncommon event
- It hardly ever happens
- Blue moon, for instance
- Poe's autograph, e.g.
- Uncommon occurrence
- Very uncommon event
- Very uncommon occurrence
- Thinness.
- A no-run, no-hit game, for instance.
- A parking place, for instance.
- Blue moon.
- Snow in Miami.
- Odd sight.
- Collector's item.
- Tenuity.
- Unusual occurrence
- Good used car, e.g.
- Curio
- Snow in Tampa, e.g.
- Hen's tooth, e.g.
- Collectible, maybe
- One in a million
- One-in-a-million thing
- Hard-to-find album
- Unusual thing
- Oddment
- Seldom-seen thing
- Thing that's seldom seen
- A one-in-a-million thing
- It's seldom seen
- Once-in-a-blue-moon occurrence
- Factor for a collector
- Appraiser's concern
- White tiger, e.g.
