Tissint - Olivine Shergottite
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Click the microscope button to view a thin section for this sample.

Fact sheet

Tissint - Olivine Shergottite

The Tissint meteorite was seen to fall at Tissint, in southern Morocco on July 18th 2011. Several large pieces (over 1 kg) and many smaller fragments were found, starting in October 2011 (a total of over 12 kg). All had a nice black fusion crust, and appeared to be very fresh and unaltered. The Tissint meteorite is a picritic basalt from Mars that is about 600 m.y. old and took about 1.1 m.y. to get here (based on cosmic ray exposure). It is classified as a depleted olivine-phyric shergottite.

Tissint is an olivine rich basalt with two generations of olivine. Large, rounded olivine megacrysts appear to be more mafic than the rock. Olivine phenocrysts are also present in the matrix, but have less magnesium and more iron. Olivine has both melt inclusions and small euhedral chromite grains. The meteorite is highly shocked, as is evidenced by maskelynite replacing original plagioclase feldspar. Other high-pressure shock phases are also reported. Tissint also contains “pods” or pockets of impact-produced glass.

This description is based on the work of NASA scientist Charles Meyer - compiler of The Mars Meteorite Compendium.

Specimen is BM2012, M3 from the NHM - currently under investigation by the OU.

About this collection

This collection of meteorites includes Shergottites, Nakhlites and Chassignites (or SNC meteorites) which originate from the surface of the planet Mars.

They carry unique signals of the surface of the planet that allows scientists to study the composition and age of Martian rocks. The collection includes a sample of the famous ALH84001 meteorite, evidence from which was used in 1996 to begin the debate of 'life on Mars?'. 


Sample details

Collection: Martian Meteorites
shergottite achondrite
Rock-forming mineral
Accessory minerals
Category guide  
Category Guide
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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: