Cascandite and jervisite, two new scandium silicates from Baveno, Italy Available to Purchase

Two new silicate minerals, cascandite and jervisite, were found as small crystals in a geode from Cava Diverio, Baveno, Italy.

Cascandite $Ca(Sc0.74Mg0.02Al0.01Fe0.222+)(Na0.01Ca0.04Mn0.10☐0.85)Si3O8.02(OH)$ or ideally CaScSi₃O₈OH, has triclinic symmetry, space group P1 with lattice dimensions a = 7.529(11)Å, b = 7.051(12)Å, c = 6.755(9)Å, α = 92°7′(5), β = 93°40′(5), γ = 104°39′(5). The X-ray powder diffraction pattern has the strongest reflections at d = 3.62(m)(200), 3.10(m) (201,121,012), 2.968(m)(021,102,012), 2.821(s)(120), 1.429(m). Cascandite is structurally related to the wollastonite–pectolite–serandite group of minerals.

Jervisite $(Na0.43Ca0.31Fe0.142+☐0.12)(Sc0.66Fe0.152+Mg0.19)Si2O6$ has monoclinic symmetry, space group C2/c with lattice dimensions a = 9.853(11)Å, b = 9.042(10)Å, c = 5.312(7)Å, β = 106°37′(7). The X-ray powder diffraction pattern has the strongest reflections at d = 6.51(w)(110), 4.51(w)(021,111), 3.038(s)(221), 2.979(m)(310), 2.543 (m)(221,002), 1.647(m)(531,440). Jervisite is a scandium pyroxene and a natural analogue of the synthetic phase NaScSi₂O₆.