Savske jame (1?), Planina pod Golico, the western Southern Karavanks.
Limonitized cast (originally siderite). The grey bands represent sphalerite.
Absence of compression in the sample indicates mineralization prior to sediment compaction. Organic decay released carbon dioxide, reacting as carbonic acid with ferrous-ion-enriched pore water to form siderite, subsequently altered into limonite.