Pernek - Krížnica antimone ore field
Pernek antimony deposit is the second largest antimonite deposit in Malé Karpaty (Little Carpathians). It is located above village Pernek, at the end of Kostolný potok (Kostolný creek), near the top od Krížnica hill. The begining of mining there dates back to the 18. century and the antimony has been exploated there until 1922. At the end of 19. century pyrite was also mined there. In 1917 a narrow-gauge railroad was buit, which led from the Pernek Railway station to the mines with length 7,5 km and was used for transport extracted ore.
Underground.
Mineralization is localized in the amphibolites with black (graphite) slates in the form of impregnations, but also forms lenses and veins. It's partially overlaped with the older pyrite-pyrrhotite mineralization. Surrounding rocks are hydrothermally changed - carbonization and chloritization. In the best quality ores was content of antimony 47-68 %, in lower quality 25 %.
Stibnite, together with quartz and carbonates are common minerals in the deposit. Other mineral species are berthierite, gudmundite, kermezite, valentinite, arsenopyrite, galena, chalkopyrite, pyrite and sphalerite. As product of weathering, antimone ores and limonite are common on heaps.
Schafarzikite
This very rare mineral species was first described in 1921 from the Pernek's antimony ore deposit. Mineral was named after the Hungarian geologist and mineralologist Ferenc Schafarzik. Schafarzikite forms prismatic crystals, black, brown or red color, with a high metallic lustre on the massive stibnite, quartz or other rocks. The size of crystals is usually up to 1 mm, rarely occurring up to 2 mm. Schafarzikite aggregates rarely cover up to 10 cm2. The Pernek - Krížnica deposit is a type locality of schafarzikite.
Schafarzikite.
Properties:
- Formula: FeSb2O4
- Class: oxides
- Crystal system: tetragonal
- Color: dark red, brown, black
- Lustre: metallic
- Hardness: 3,5 (Mohs)
- Specific gravity: 4,3 g.cm-3