Alloriite
A feldspathoid silicate of the cancrinite subgroup, known only from Italy and named for mineralogist Roberto Allori.
Intro adapted from Wikipedia (CC BY-SA).
Alloriite is an IMA-recognized mineral species in the silicate class, with the chemical formula (Na,K,Ca)₂₄(Na,Ca)₄Ca₄(Si,Al)₄₈O₉₆(SO₄)₄(SO₃,CO₃)₂(OH,Cl)₂(H₂O,OH)₄.
It crystallizes in the hexagonal crystal system (space group P31c). It is a member of the Cancrinite, Cancrinite-sodalite structural group.
Key properties: Mohs hardness 5; specific gravity 2.35; White streak; Vitreous luster; optically uniaxial.
IMA symbol Aor, IMA status: approved, named in 2006.
Lining the walls of small miarolitic cavities in a sanidine-syenite volcanic bomb.
It is found associated with Sanidine, biotite, andradite, apatite.
The mineral was named to honor Roberto Allori (b. 1933), an amateur mineralogist who has studied the Latium region.