Sample 15415 or the Genesis Rock was collected by Apollo 15 astronauts James Irwin and David Scott on the surface of the moon. The date was 01 August 1971 and it was the second EVA for the astronauts when Sample 15415 was collected from Spur crater.
The early idea was the Genesis Rock was lunar primordial crust, however it turn out not to be so. The rock is anorthosite.
The name Genesis Rock is stored at the Lunar Sample Laboratory Facility.
Here’s a written transcript of the astronaut radio transmissions at the time of the finding and below (should be) the audio file.