Bonacinaite as a group of two lath-shaped light violet and eight dark purple-blue crystals in a very small void of a quartz–braunite matrix. Field of view: 0.3 mm. Picture: Giorgio Maria Bortolozzi. — Photo: Giorgio Maria Bortolozzi · CC BY 4.0
Bonacinaite
Bonacinaite is an IMA-recognized mineral species in the arsenate class, with the chemical formula Sc(AsO₄)·2H₂O.
It crystallizes in the monoclinic crystal system (space group P2_1/n). It is a member of the Phosphosiderite structural group.
Key properties: specific gravity 2.634; Vitreous luster.
IMA symbol Bci, IMA status: approved, named in 2018.
Found in a small void in a metamorphosed manganese deposit.
It is found associated with Braunite, quartz, manganese oxides, corroded arseniopleite.
The mineral was named to honor Enrico Bonacina (b. 1928), dean of micromineral photography in Italy.