Clarity: Clarity assesses the internal characteristics of the diamond as it formed in nature. This C factor is graded on a 10-grade scale and also impacts the diamond's rarity and value.
The fastest marathon ever was run by Geoffrey Mutai (2:03:02) at the Boston Marathon on April 18, 2011. But because the legendary Boston course does not meet IAAF layout standards, the World Record belongs to Patrick Makau (2:03:38) recorded at the Berlin Marathon on September 25, 2011.
Fastest menâs time: Kenyaâs Geoffrey Mutai ran the Boston Marathon in 2 hours, three minutes, and two seconds in 2011. At the time, it was a world-record pace. Fastest womenâs time: Kenyaâs Rita Jeptoo ran the race in 2 hours, 18 minutes, and 57 seconds in the 2014 Boston Marathon, and set the womenâs course record.