Outstanding orange sharp crystals of the very rare mineral strontio-orthojoaquinite associated to leucosphenite, magnesioriebeckite and albite from the type locality in Japan for the first mineral (Kinzandani, Ohmi, Itoigawa City, Niigata, Honshu Island, Japan). Ex-Alfredo Petrov specimen. — Photo: David Hospital · CC BY-SA 4.0
Strontio-orthojoaquinite
Strontio-orthojoaquinite is an IMA-recognized mineral species in the silicate class, with the chemical formula NaSr₄Fe³⁺Ti₂Si₈O₂₄(OH)₄.
It crystallizes in the orthorhombic crystal system (space group P2_1am). It is a member of the Joaquinite structural group.
Key properties: Mohs hardness 5.5; specific gravity 3.62; optically biaxial.
IMA symbol Sojq, IMA status: approved, named in 1979.
Found in an amphibolite-quartz-albitite dike cutting serpentinite.
It is found associated with Benitoite, leucosphenite.
The name refers to its strontium content, ORTHOgonal crystal system, and relation to joaquinite.