Genesis Rock

The Genesis Rock (sample 15415) is a sample of Moon rock retrieved by Apollo 15 astronauts James Irwin and David Scott in 1971 during the second lunar EVA, at Spur crater on Earth's Moon.

With a mass of c. 270 grams (4,200 grains),[1] it is currently stored at the Lunar Sample Laboratory Facility in Houston, Texas.

Chemical analysis of the Genesis Rock indicated it is an anorthosite, composed mostly of a type of plagioclase feldspar known as anorthite.

The rock was formed in the early stages of the Solar System, at least 4 billion years ago.

Dating of pyroxenes from other lunar anorthosite samples gave a samarium–neodymium age of crystallization of 4.46 billion years.

The Genesis Rock
The Genesis Rock on the lunar surface prior to sampling (left of the gnomon , which was used for scale in the photos)
The Genesis Rock on display at the Lunar Sample Laboratory Facility
The discovery of the Genesis Rock