Limonitna siga

**Limonitna siga** V Sloveniji je bilo odkritih že več kot 12.500 kraških jam in brezen. Velika večina sige v njih je iz kalcijevega karbonata, predvsem iz kalcita. V rudniku Sitarjevec pa rastejo kapniki iz limonita, ki je zmes železovih oksidov in hidroksidov. Njihova posebnost je v tem, da pri rasti sodelujejo mikroorganizmi, zrastejo pa tudi do 5 cm na leto. Zbirka Prirodoslovnega muzeja Slovenije. **Limonite speleothem ** In Slovenia, more than 12,500 karst caves and pitches have been discovered so far. The vast majority of speleothems in them are composed of calcium carbonate, predominantly calcite. In the Sitarjevec mine, however, stalactites made of limonite, a mixture of iron oxides and hydroxides, are growing. Their special feature lies in the fact that microorganisms take part in their growth, and they do grow no less than up to 5 cm per year. Collection of the Slovenian Museum of Natural History.