May 2024 – Olivine

In May 2024, olivine holds the title of Mineral of the Month. However, olivine actually covers a mixed series of forsterite to fayalite. This means that there is a magnesium-rich end member (forsterite) and an iron-rich end member (fayalite). In such a solid solution, one element can be substituted by another element. With olivine, this is unconditional. It is therefore possible to find an olivine with completely different magnesium and iron contents. What is exciting for scientific questions is that the magnesium to iron ratio can tell us something about the conditions under which the olivine and therefore the rocks were formed. Olivine is found in magmatic rocks in particular and is one of the main minerals of peridotite, which makes up most of the Earth’s mantle. The particularly pure, transparent-green variant of olivine is also used as a gemstone. Olivine is also used in the production of heat-resistant glass and fireproof materials.