Odigitriaite
Odigitriaite is an IMA-recognized mineral species in the silicate class, with the chemical formula CsNa₅Ca₅[Si₁₄B₂O₃₈]F₂.
It crystallizes in the monoclinic crystal system (space group C2/c).
Key properties: Mohs hardness 5; specific gravity 2.8; White streak; Vitreous luster; optically biaxial.
IMA symbol Odi, IMA status: approved, named in 2015.
Found in glacial cobbles in moraine derived from an alkaline massif.
It is found associated with Sr-rich fluorite, pekovite, mendeleevite-(Се), orlovite, kirchhoffite, neptunite, zeravshanite, senkevichite, nordite-(Ce), alamosite, hyalotekite, khvorovite.
Its name comes from the Greek Oδηγήτρια, with the meaning “she who shows the way, ” to emphasize the role of Cs as a major indicator of extreme fractionation.