76535 (54) - Troctolite
Click the microscope button to view a thin section for this sample.
Click the microscope button to view a thin section for this sample.

Fact sheet

76535 (54) - Troctolite

Sample 76535 is of troctolite, a coarse-grained igneous rock that crystallised below the surface of the moon, but was excavated by later meteorite impacts. It exhibits evidence of shock after its original formation. This sample was collected as part of a rake sample at Station Six during the Apollo 17 mission. Near to where this sample was found was Tracy’s Rock – one of the largest boulders visited by the Apollo astronauts.

In thin section the rock has a granular, polygonal texture consisting of olivine and plagioclase feldspar crystals. Note: This thin section has been previously used for electron microprobe analysis and therefore shows residual traces of a carbon coating applied for this technique, considerable shattering (caused during sample preparation) and major fracturing where it has been broken and repaired.

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

Additional images
About this collection

Apollo 17, the final manned landing mission, had two objectives: to obtain samples of ancient rocks from the lunar highlands and to look for evidence of younger volcanic activity on the valley floor.

This small Collection contains material deriving from both periods, including igneous rocks around 4.3 billion years old from the lunar highlands as well as younger volcanic samples dating from about 3.6 billion years ago.

Apollo 17 was launched on 7 December 1972.

Sample details

Collection: Apollo 17
Rock-forming mineral
Category guide  
Category Guide
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.
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.
Selecting one or more period, for example 'Jurassic'.
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.
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).
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: