Associated minerals are: epsomite, members of the "hair salt" family (the most abundant of which is apjohnite), gypsum, jarosite, tschermigite, diadochite and four other new species: levinsonite-(Y), zugshunstite-(Ce), the probable ammonium analogue of slavikite
and an iron phosphate.
A very rare secondary mineral found in old workings of the Andrassy III section, slavikite occurs as yellowish green, hexagonal tabular crystals up to 1 mm in diameter, associated with other sulfate minerals (Szakall et al., 1997).
Recently, slavikite has been identified by X-ray analysis in the dumps of the open pit in the Pezinok mine (Trtikova, personal communication, 1997).
Alum Cave Bluff, a Dana locality for apjohnite, epsomite, melanterite and potash alum, has yielded good microcrystals of several rare sulfate minerals, including three new rare-earth sulfates, and is the first North American occurrence of slavikite.
A search of the powder-pattern files revealed that the mineral was slavikite, a ferric magnesium sulfate previously u nreported from North America.
Slavikite, a rare (or rarely identified) mineral worldwide, appears to form near the surface of masses of mixed hair salt and epsomite, and is probably produced by a reaction such as that below:
[right arrow] 4Na[Mg.sub.2][[Fe.sup.3+].sub.5][([SO.sub.4]).sub.7]/[(OH).sub.6]*33[ H.sub.2]O + slavikite
Magnesiocopiapite is easily found and identified by its bright yellow color, The distinctive yellow-green hue of slavikite can perhaps be noted by the sharp-eyed, but the amounts are generally so small that it is difficult to find.
Exceptions are ammoniojarosite and destinezite (nearly insoluble); gypsum (slightly soluble); and slavikite (slowly soluble with decomposition).
The mineral shows good cleavage normal to plates, and is found associated with magnesian apjohnite and epsomite, and sometimes with slavikite, ammoniojarosite, tschermigite, levinsonite-(Y), or zugshunstite-(Ce).