Publication details
Redefinition of theresemagnanite, NaCo4(SO4)(OH)(6)C1.6H2O: new data and relationship to 'cobaltogordaite'
| Authors | |
|---|---|
| Year of publication | 2018 |
| Type | Article in Periodical |
| Magazine / Source | Mineralogical Magazine |
| MU Faculty or unit | |
| Citation | |
| Web | http://dx.doi.org/10.1180/minmag.2017.081.030 |
| Doi | http://dx.doi.org/10.1180/minmag.2017.081.030 |
| Keywords | theresemagnanite; 'cobaltogordaite'; redefinition; sodium cobalt sulfate; X-ray diffraction; gordaite group; oxidation zone; Cap Garonne mine; Blue Lizard mine |
| Description | Theresemagnanite was riginally described frm the Cap Garnne mine, Var, France. Its ideal frmula was reprted as (C,Zn,Ni)(6)(S-4)(H,Cl)(10).8H(2)O; withut crystal structure data, nly the pwder X-ray diffractin pattern was given. Revisin f the hltype material revealed that theresemagnanite is identical t cbaltgrdaite (IMA2014-043), recently described frm the Blue Lizard mine, Utah, USA. Theresemagnanite is thus redefined in accrdance with the new data btained fr the netype specimen frm Blue Lizard (frmerly the hltype specimen f cbaltgrdaite) and cbaltgrdaite has been discredited by the Internatinal Mineralgical Assciatin Cmmissin n New Mineral Nmenclature and Classificatin (IMA CNMNC). Theresemagnanite has the ideal, end-member frmula NaCo4(SO4)(OH)(6)Cl.6H(2)O. The empirical frmulae f the hltype (Cap Garnne) and the netype (Blue Lizard), bth based n micrprbe analyses and calculated n the basis f 17 O | Cl atms per frmula unit (with fixed 6 H grups and 6 H-2 mlecules; H cntent is calculated by stichimetry) are (Na0.64K0.09)Sigma(0.73)(Co2.35Zn1.22Ni0.50)(Sigma 4.07)S1.02O3.98(OH)(6)Cl-1.02.6H(2)O and Na-1.01(Co1.90Zn1.37Ni0.48Cu0.15Mn0.05)(Sigma 3.95)S1.03O4.09(OH)(6)Cl-0.91.6H(2)O, respectively. Theresemagnanite is trignal, P3, a = 8.349(3), c = 13.031(2) angstrom, V = 786.6(4) angstrom 3 and Z = 2 (netype). The strngest pwder X-ray diffractin lines are [d(obs) in angstrom (hkl) (I-rel)]: 13.10 (001)(100), 6.53 (002)(8), 4.173 (110)(4), 3.517 (112)(5), 2.975 (10<(4)ver bar>, 10 )(4), 2.676 (211)(5) and 2.520 (12<(2)ver bar>)(5) (netype). Theresemagnanite is a cbalt analgue f grdaite, NaZn4(SO4)(OH)6Cl.6H(2)O. These minerals represent the grdaite grup, accepted by the IMA CNMNC. |