Abstrakt
Javorieite, KFeCl3, is a new mineral, commonly hosted by salt melt inclusions enclosed in vein quartz in the Biely Vrch porphyry gold deposit, in the Central Slovakia Volcanic Field in the Western Carpathians. The mineral name refers to the Javorie stratovolcano, which hosts most porphyry gold systems in this volcanic field.
Within the inclusions, javorieite occurs in the form of small (up to 15 µm) green anhedral crystals with high relief, which melt in the range 320-338 °C when heated. It is extremely hygroscopic and readily oxidised if exposed to the air.
The daughter mineral was identified through comparison with the Raman spectra of the synthetic analogue, and through data obtained with the FIB-SEM-EBSD analytical technique. The combination of the three independent analytical tools on three different inclusions proved the match in chemistry and crystallography with synthetic KFeCl3.
Javorieite is orthorhombic, the unit-cell parameters are a = 8.715(6) Å, b = 3.845(8) Å, c = 14.15(3) Å, V = 474.16(3) Å3, Z = 4. Furthermore, the experimental data in the NaCl-KCl-FeCl2 system agree with the microthermometric behaviour of javorieite.
The presence of javorieite in three other localities in this volcanic field was established by Raman spectroscopy. The distinctive Raman spectrum of javorieite (main bands at 66-69, 108-109, 119-120, 134-135, 235-237 cm-1) can help in future studies of salt melt inclusions worldwide, including a quick recognition of shallow porphyry systems that can be potentially enriched in gold.