Sivuviite

Sivuviite is a rare mineral discovered in 1993, named after the Sivunpää mine in Finland where it was first found. It is a complex oxide mineral with the chemical formula Na4Ca2Mn3+3Fe3+2Ti2Si6O24. Sivuviite crystallizes in the monoclinic crystal system and typically forms small, dark brown to black crystals or granular masses. Its hardness on the Mohs scale is approximately 5.5, and it has a specific gravity of around 3.6.

Sivuviite is notable for its unique chemical composition and the presence of both trivalent manganese (Mn3+) and trivalent iron (Fe3+) in its structure. This makes it a member of the epidote group, which includes minerals like epidote and piemontite. The mineral is typically found in granitic pegmatites and is associated with other rare minerals such as eudialyte and astrophyllite.

Due to its rarity and the difficulty in obtaining large, well-formed crystals, sivuviite is not commonly used in jewelry or other applications. However, it is of interest to mineral collectors and researchers studying the complex chemistry of rare minerals. The study of sivuviite contributes to the understanding of mineral formation processes and the diversity of mineral species found in granitic pegmatites.