One of the most significant ore mineralizations in the Carpathians is the Slovak Ore Mountains. There are several ore deposits here, one of the most important of which is in Rožňava, where about 42 ore veins are known in an area of 48 km2. Here, mainly iron and copper ores are mined. Production began in 1291 and ongoing to this day. About 120 minerals have been described from this area; economically the most important of these is iron carbonate (FeCO3), i.e. siderite, which is a common, albeit a rather poor grade ore of iron.
In the picture: Siderite, Rožňava (Slovakia). Image width: 8 cm. Photo by KDS project.