rarity
n. C / Un. something that is very unusual or does not happen often. It can also mean the quality of being hard to find.
n. the quality of being infrequent or scarce; a person or thing that is particularly uncommon.
Snow in this part of the country is a real rarity.
Genuine first editions of this novel are a rarity and often sell for thousands of dollars at auction.
The scientist noted that while the mineral is common in volcanic regions, its presence in sedimentary rock is a geological rarity that warrants further investigation.
From rare + -ity, borrowed from Middle French rarité, from Latin rāritās; compare French rareté. See also rare.
Uncountable when referring to the abstract quality of being scarce; countable when referring to a specific rare object or event.