Based on the clue '1 of only 2 birthstones whose names begin with the...', what is the answer?

Based on the clue '1 of only 2 actors who directed themselves to a be...', what is the answer? What is associated with: 1 of only 2 americans to win the mens figure skating gold medal since 1960? Based on the clue '1 of only 2 animated films on the list', what is the answer? Based on the clue '1 of only 2 asian cities that hosted the summer ol...', what is the answer? What is associated with: 1 of only 2 jockeys to ride to over 8000 wins? Based on the clue '1 of only 2 species of eagle to breed in the us c...', what is the answer? Based on the clue '1 of only 2 us presidents to win the prize', what is the answer? Based on the clue '1 of only 3 authors to win 2 pulitzer prizes for f...', what is the answer?