Assertion: clock | /r/HasProperty | one of the rarest things
Facets:
Source sentences:
text: The Clock is one of the rarest things available to scientists: an easily recognizable icon that can grab a passerby with no scientific background.
text: Most clocks made in the United States before 1840 were fabricated by hand in small clockmaking shops and any remaining examples of these clocks are rare and collectible pieces.