White crystal aggregates of the rare Sr mineral stronalsite from Mount Ohsa, Niimi City, Okayama Prefecture, Honshu Island, Japan. Ex Vandenbroucke Museum collection from Waregem, Belgium. — Photo: David Hospital · CC BY-SA 4.0
Stronalsite
Stronalsite is an IMA-recognized mineral species in the silicate class, with the chemical formula Na₂SrAl₄Si₄O₁₆.
It crystallizes in the orthorhombic crystal system (space group Iba2).
Key properties: Mohs hardness 6.5; specific gravity 2.95; White streak; Vitreous luster; optically biaxial.
IMA symbol Sns, IMA status: approved, named in 1983.
A secondary alteration mineral in veins cutting mafic metatuff xenoliths (Rendai, Japan); in veinlets and grains in jadeitic aggregates within serpentinite (Mt. Ohsa, Japan).
It is found associated with Pectolite, slawsonite, albite, calcite, aragonite, natrolite, thomsonite, prehnite, datolite, rosenhahnite, vuagnatite.
The name refers to STRONtium and ALuminum in its composition.