Szomolnokite
Szomolnokite Halotrichite (Hal); szomolnokite (Szo) and voltaite (Vol)
Category Sulfate mineral Formula (repeating unit) Fe2+ SO4 · H2 O IMA symbol Szo[1] Strunz classification 7.CB.05 Dana classification 29.6.2.2 Crystal system Monoclinic Crystal class Prismatic (2/m) Space group C2/c (no. 15)Color Sulfur -yellow, yellow-brown, red-brown, blue, colorlessCrystal habit Bipyramidal, distorted, tabular, parallel growths, globular, stalactites Fracture Conchoidal to sub-conchoidal, uneven Tenacity Brittle Mohs scale hardness 2.5 Luster Vitreous Diaphaneity Translucent Specific gravity 3.03–3.07 (measured), 3.10 (calculated) Optical properties Biaxial (+), colorless (transmitted light) 2V angle 80° (measured), 86° (calculated) References [2] [3] [4] [5]
Szomolnokite (Fe2+ SO4 ·H2 O) is a monoclinic iron sulfate mineral forming a complete solid solution with magnesium end-member kieserite (MgSO4 ·H2 O).[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]
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
^ 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 .
^ a b c d Mindat.org - Szomolnokite
^ a b Webmineral - Szomolnokite
^ a b Handbook of Mineralogy - Szomolnokite
^ 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.
^ 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
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.