12005 - Magnesium-rich basalt
Collection:
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Click the microscope button to view a thin section for this sample.
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Fact sheet

12005 - Magnesium-rich basalt

Sample 12005 is a lunar Mare basalt collected during the Apollo 12 mission to the Moon. The sample contains the highest magnesium content of all lunar basalts and is similar to primitive picritic basalts on Earth. Although the age of this sample has not been determined, most Mare basalts are between 3 and 3.5 billion years old. The top surface of the hand specimen sample is covered in micrometeorite craters, otherwise known as zap pits.

The thin section of this sample exhibits a cumulate texture, formed when dense crystals settle within a partially crystallised magma. Cumulate textures are also observed in some basalt and gabbro rocks on Earth. The rock contains abundant olivine and pyroxene (augite and pigeonite) phenocrysts and interstitial plagioclase feldspar. Minor amounts of ilmenite and chrome spinel are also present. 

About this collection

Sample details

Type
igneous
Category
mare basalt
Rock-forming mineral
olivine
feldspar
pyroxene
Accessory minerals
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: