15415 (16) Ferroan Anorthosite
Collection:
Apollo 15
Click the microscope button to view a thin section for this sample.
Microscope
Click the microscope button to view a thin section for this sample.
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Fact sheet

15415 (16) Ferroan Anorthosite

15415 is a coarse-grained plagioclase-rich rock, and is one of the best-known Moon rocks. It was collected from the rim of Spur Crater and given the name ‘Genesis Rock’ by the astronauts of Apollo 15. They had been looking for evidence of the Moon’s early-formed crust and they declared they had found what they were looking for when they came across this. It is one of the oldest rocks they collected.

In addition to the 98% of plagioclase feldspar present, the rock contains minor pyroxene, ilmenite and silica. The grain size of the plagioclase reaches 1.8cm. The rock has been close to the Moon’s surface for much of its life and the grains show evidence of shock cracking and fracturing.

The sample weighed 269.4 grams before analysis. The metamorphic overprint on this sample precluded an accurate age date but a good estimate is ~4 billion years (Ar/Ar).

Further details of this and other Apollo samples are here: http://curator.jsc.nasa.gov/lunar/

Additional images
 
  • Lunar surface close to the 15415 sample location
  • The Apollo 15 lunar buggy close to 15415 sample location
About this collection
 
Apollo 15

The Apollo 15 landing site was in the Apennine Highlands, and close to Hadley Rille — a long, narrow winding valley. Approximately 76 kg of lunar material, including soil, rock, core-tube and deep-core samples, were returned to Earth.

This mission was the first flight of the Lunar Roving Vehicle which allowed the astronauts to venture further from the Lunar Module than in previous missions. During three periods of extravehicular activity, or EVA, on July 31st, and August 1st and 2nd, Scott and Irwin completed a record 18 hours, 37 minutes of exploration, travelling 17.5 miles, in the first car that humans had ever driven on the Moon.

Apollo 15 was launched on 26 July 1971.

Sample details

Collection: Apollo 15
Type
igneous
Rock-forming mineral
plagioclase
feldspar
Accessory minerals
pyroxene
ilmenite
Category guide  
Category Guide
Title
Refers to any word or phrase that appears in the individual rock names. Names are generally descriptive; they allow users to search for broad terms like ‘granite’ as well as more specific names such as ‘breccia’. However, the adjacent descriptions of the specimens captures a wider range of general words and phrases and is a more powerful search tool.
Description
Refers to any word or phrase that appears anywhere in the descriptions of the specimens
Accessory minerals
Minerals that occur in very low abundance in a rock. They are usually not visible with the naked eye and contribute perhapssver, they often dominate the rare elements such as platinum group metals.
Rock-forming minerals
Minerals that make up the bulk of all rock samples and are also the ones used in rock classi?cation.
Timescale
Selecting one or more period, for example 'Jurassic'.
Theme
A term used to group together related samples that are not already gathered into a single Collection. For instance, there is a ‘SW England granites’ theme that includes such rock types as granite, hydrothermal breccia, skarn and vein samples.
Category
A general term used to label a rock sample. It is a useful way of grouping similar samples throughout a collection. Category names are often, but not exclusively, common rock names (e.g. granite, basalt, dolerite, gabbro, greisen, skarn, gneiss, amphibolite, limestone, sandstone).
Owner
The owner of the sample that appears in the collection. For example, NASA owns all the samples that appear in the Moon Rocks collection
We would like to thank the following for the use of this sample:

More from this collection

Apollo 15