79215 (50) Feldspathic Granulitic Impactite
Collection:
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.
Microscope

Fact sheet

79215 (50) Feldspathic Granulitic Impactite
79215 is a holocrystalline, feldspar-rich rock with a granoblastic texture that was formed by a high temperature metamorphic process of unknown origin. It is apparently an annealed aggregate of relict anorthositic and troctolitic cumulates, with an added meteoritic component. Equant plagioclase grains meet at 120 degree triple junctions with smaller intersertal grains of olivine, pyroxene and opaque minerals. Within 79215 are numerous “oxide complexes” with surrounding reaction corona. These complexes consist of core assemblages which may include spinel, ilmenite, armalcolite, troilite, rutile and metallic iron which are surrounded by a corona of plagioclase and occasionally olivine. Chromite spinel is the dominant constituent of the oxide assemblages.

The sample weighed 553.8 grams before analysis and has been dated at 4.03±0.02 billion years old (Ar/Ar).

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

This sample has previously been gold coated and residual gold is still present around the sample.
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
Type
metamorphic
Rock-forming mineral
olivine
pyroxene
plagioclase
Accessory minerals
spinel
ilmenite
armalcolite
troilite
rutile
metallic iron
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