Secret messages from the Earth's interior: Diamonds decode the Earth!

Secret messages from the Earth's interior: Diamonds decode the Earth!

In the fascinating world of geology, diamonds are much more than just sparkling pieces of jewelry. These ancient messengers from the Earth's mantle offer invaluable insights into the deep processes of our planet. On December 2, 2025, Dr. Beth Kahle from the LMU Department of Earth and Environmental Sciences talks about the importance of these crystals for our understanding of the Earth. Her lecture entitled “Diamonds – Messengers from the Earth’s Mantle” will be offered both on site and online via Zoom. Admission is free, and those interested can visit the website of the “Friends of the Geological State Collection Munich e.V.” obtain further information.

Dr. Kahle will shed light on the exciting history of diamond discovery and exploration in southern Africa. She presents current scientific findings that have been gained from the detailed study of these minerals. A particular focus is on Dr. Kahle for the analysis of diamonds that were examined in their host rock, the eclogite, using computer tomography.

Insight into the geological processes

By studying corresponding inclusions, diamonds can provide information about the Earth's interior up to 800 kilometers deep. An exciting study on the topic comes from scientists led by Prof. Frank Brenker from Goethe University. This shows that diamonds in the Earth's mantle are not only transported upwards, but can also migrate downwards under certain conditions. The researchers examined a 1.4-carat diamond from the Central African Republic and found unusual mineral inclusions. Analysis of the carbon and nitrogen isotopes made it clear that this diamond originated in the upper mantle and then moved into the deeper transition zone of the mantle. Another example that shows that diamonds can reveal more about the internal structure of the Earth than previously thought is the publication “Ringwoodite and zirconia inclusions indicate downward travel of super-deep diamonds” by Sofia Lorenzon and her colleagues.

The Earth's mantle itself extends from about 30 to 2,900 kilometers below the Earth's surface and is one of the main layers of our planet. With a wealth of silicate minerals rich in magnesium and iron, the mantle makes up the majority of Earth's volume. Scientists agree that studying this otherwise inaccessible part of the Earth is crucial to understanding geological processes and phenomena such as earthquakes and volcanism. Methods such as seismic waves and geophysical measurements are used.

Despite the challenges posed by the depths of the Earth, the potential for new insights is huge. This is how Dr. Kahle not only expands the existing knowledge about diamonds, but also opens doors to current questions in geology. It remains exciting to see what new discoveries and advances still await us in this area. Anyone who would like to find out more about the adventures of these “messengers from the Earth’s mantle” should listen to the lecture by Dr. Don't miss Kahle.