Publication details
Ferroefremovite, (NH4)2Fe2+2(SO4)3, a new mineral from Solfatara di Pozzuoli, Campania, Italy
| Authors | |
|---|---|
| Year of publication | 2021 |
| Type | Article in Periodical |
| Magazine / Source | Canadian Mineralogist |
| MU Faculty or unit | |
| Citation | |
| Web | https://pubs.geoscienceworld.org/canmin/article-abstract/59/1/59/593147/Ferroefremovite-NH4-2Fe2-2-SO4-3-a-new-mineral |
| Doi | http://dx.doi.org/10.3749/canmin.1900085 |
| Keywords | ferroefremovite; sulfate; ammonium; new mineral; Solfatara di Pozzuoli; Italy |
| Description | The new sulfate mineral ferroefremovite, ideally (NH4)(2) Fe-2(2+)(SO4)(3), was discovered at the "Bocca Grande" fumarole, Solfatara di Pozzuoli, Flegrean Volcanic Complex, Naples Province, Campania, Italy. Associated minerals are adranosite, adranosite-(Fe), godovikovite, huizingite-(Al), mascagnite, and opal. Ferroefremovite forms cubic crystals up to 0.1 mm across. The new mineral is colorless and has a vitreous luster and white streak. it is brittle and has an uneven fracture. No cleavage or parting are observed. Mohs hardness is 2. D-mens. =2.69(1) g/cm(3) . D-calc.= 2.700 g/cm(3) . Optically, ferroefremovite is isotropic, n = 1.574(3) (lambda= 589 nm). It is non-pleochroic. The presence of the NH4+ cation is confirmed by the Raman spectrum. The chemical composition of ferroefremovite is (wt.%; electron microprobe, N determined by CNH analysis) (NH4)(2)O 11.51, Na2O 0.11, K2O 1.35, MgO 8.38, MnO 0.98, FeO 18.94, SO 3 57.08, total 98.35. The empirical formula based on 12 O apfu is [(NH4)(1.85)K0.12Na0.01]Sigma 2.04S2.99O12. Ferroefremovite is cubic, space group P2(1) 3, with a = 10.0484(9) A, V = 1014.59(16) angstrom(3) , and Z = 4. The strongest lines of the powder X-ray diffraction pattern [d, angstrom (I, %) (hkl)] are 5.80 (40) (111), 4.50 (20) (201, 210), 4.11 (30) (211), 3.17 (100) (310, 301), 3.02 (20) (311), 2.68 (50) (312, 321), 1.86 (18) (502, 432), 1.62 (18) (523, 532, 611). |