Related Clues:
- Like astatine, among all naturally occurring elements
- AB negative, among blood types
- Least common in Connemara restoration
- Like AB negative, among blood types
- Most collectible, perhaps
- Sartre (anag) — most uncommon
- Most unusual artist on break
- Least frequent
- Most endangered
- Sartre turned out to be most unusual
- It's most uncommon for artist to relax
- Rex needs a break — most unusual
- Others holding artist up? Most unusual
- Most economical spring break
- Most valuable, to a collector