johdinliite
Johdinliite is a rare mineral discovered in 2019, named after the Finnish word "johdin," meaning "path" or "way," reflecting its unique crystal structure and formation. It is a complex oxide mineral, with the chemical formula (Na,Ca)2(Fe,Mn)2Ti2O8. Johdinliite is typically found in alkaline igneous rocks, particularly in carbonatites, and is often associated with minerals such as aegirine, astrophyllite, and perovskite. Its crystal system is monoclinic, and it exhibits a distinct prismatic habit with a pale yellow to brown color. Johdinliite is of interest to mineralogists and geologists due to its unusual composition and the specific geological conditions under which it forms. Despite its rarity, johdinliite provides valuable insights into the complex processes involved in the formation of alkaline igneous rocks and the mineralogy of rare earth elements.