The optical identification of minerals can be carried out by preparing a suitable sample and studying it through a petrographic microscope.
For this, the Canary Museum of Meteorites has its petrographic laboratory, where we prepare the thin sections of the samples for later study under a microscope.
This technique allows us to know if the studied rock is a meteorite or not, and to determine the compatibility with the known typologies, to be able to issue the corresponding certificate.
In accordance with official protocols, the types of meteorites known are currently well identified, so it is possible to carry out the identification of them in the hand samples that turn out to be. For this we resort to various analytical techniques, the first of them will be petrographic analysis.
By applying the polarized light microscopy technique, it is possible to identify rocks and minerals in thin section, the study of textures, structural alterations and many other data that will allow us to characterize meteorites.
According to the protocols, there will be occasions when it becomes necessary to carry out more specific, geochemical or isotope analyzes, in which case the client will be contacted to carry out the donation of the samples and the payment of the corresponding fees.
It begins by preparing a polished sample and a thin sheet section for later optical and petrographic microscopic study by polarized light. If the sample is identified as a meteorite, its documentation and issuance of the certificate of authenticity (if authentic) are carried out.
In order to carry out this study, a sample of the rock is needed to make a polished surface and thin sections. The sample must not be smaller than 2 x 2 centimeters, as you can see in the corresponding section. A suitable surface is necessary to carry out the petrographic study. The Laboratory will NOT accept smaller samples, given the impossibility of working with them.
It is important that the sample has, if possible, a part of the outer zone and a part of the interior.
WHY A POLISHED SECTION AND A THIN SECTION?
The first test to which the sample is subjected is carried out with a geological optical microscope, incident light, and on a polished surface. In most cases it is enough to know whether or not the rock is a meteorite. If it were meteorite, or if there was still any doubt about its nature, we proceed to the study of a thin section in the microscope after equipping it with the corresponding polarizing filters, with which to know the mineral composition and document textures and components in order to its certification.
We enclose in this page a scheme of the procedure that will be carried out, approved in protocol 01/2016 of the MCM for the IDENMET program (Meteorite Identification and Certification).
The final step towards the official classification is not mandatory, although it is recommended, and such a procedure is another independent of this, involving the donation of new samples and the payment of fees that have been imposed by the Universities where we will carry out the process.
This laboratory does NOT work with photographs or issue conclusions or opinions without prior scientific study of a physical sample of the rock.