Szomolnokite (Fe2+SO4·H2O) is a monoclinic iron sulfate mineral forming a complete solid solution with magnesium end-member kieserite (MgSO4·H2O).[2] In 1877 szomolnokite's name was derived by Joseph Krenner from its type locality of oxidized sulfide ore containing iron in Szomolnok, Slovakia (Hungary at the time).[2][3][4]

Szomolnokite
Halotrichite (Hal); szomolnokite (Szo) and voltaite (Vol)
General
CategorySulfate mineral
Formula
(repeating unit)
Fe2+SO4 · H2O
IMA symbolSzo[1]
Strunz classification7.CB.05
Dana classification29.6.2.2
Crystal systemMonoclinic
Crystal classPrismatic (2/m)
Space groupC2/c (no. 15)
Identification
ColorSulfur-yellow, yellow-brown, red-brown, blue, colorless
Crystal habitBipyramidal, distorted, tabular, parallel growths, globular, stalactites
FractureConchoidal to sub-conchoidal, uneven
TenacityBrittle
Mohs scale hardness2.5
LusterVitreous
DiaphaneityTranslucent
Specific gravity3.03–3.07 (measured), 3.10 (calculated)
Optical propertiesBiaxial (+), colorless (transmitted light)
2V angle80° (measured), 86° (calculated)
References[2][3][4][5]

As of mid-January 2020 the only continent on which szomolnokite has not been found and reported is Antarctica.[2]

At room temperature szomolnokite is stable up to a pressure of 6.2 GPa, and then transforms into triclinic crystal structure.[6]

References

edit
  1. ^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
  2. ^ a b c d Mindat.org - Szomolnokite
  3. ^ a b Webmineral - Szomolnokite
  4. ^ a b Handbook of Mineralogy - Szomolnokite
  5. ^ Wildner, M.; Giester, G. (1991). "The crystal structures of kieserite-type compounds. I. Crystal structures of Me(II)SO4*H2O (Me = Mn,Fe,Co,Ni,Zn)". Neues Jahrbuch für Mineralogie - Monatshefte. 1991: 296–306.
  6. ^ Meusburger, J. M.; Ende, M.; Talla, D.; Wildner, M.; Miletich, R. (2019-09-01). "Transformation mechanism of the pressure-induced C2/c-to-P1¯ transition in ferrous sulfate monohydrate single crystals". Journal of Solid State Chemistry. 277: 240–252. doi:10.1016/j.jssc.2019.06.004. ISSN 0022-4596. S2CID 197070809.

Bibliography

edit
  • Palache, P.; Berman H.; Frondel, C. (1960). "Dana's System of Mineralogy, Volume II: Halides, Nitrates, Borates, Carbonates, Sulfates, Phosphates, Arsenates, Tungstates, Molybdates, Etc. (Seventh Edition)" John Wiley and Sons, Inc., New York, pp. 479–480.