Leonard Nimoy: Fans Describe What Made Spock Such a Memorable Character

— -- As news of actor Leonard Nimoy's death spread today, fans mourned the loss of the "Star Trek" star.

Nimoy, who starred as the emotionless half-human, half-Vulcan in the TV show and several films, died at the age of 83, but to Trekkies, his memory will live on.

"R.I.P Mr. Nimoy," wrote a "World News Tonight" fan on Twitter. "You will forever be remembered."

ABC News asked readers what made Nimoy's Spock such a beloved, iconic character and to share their favorite memories.

From his appearance to his demeanor, here's what they said.