Smålands Taberg, Jönköping, Sweden
This is a nice one to show as this type of ore is pretty rare. The Taberg orebody consists of titanomagnetite olivenite, additionally rich in vanadium. It contains about 35% titanomagnetite, with 6 % titanium based on the oxide. Vanadium content is about 0.3%. The deposit was mined from 1939 to 1960; the mine left two large craters easily visible on aerial photographs. Today the mine is part of a nature reserve, collecting is forbidden.
Polished slab of the typical ore (13 cm wide):
The samples are pretty uniform, consisting of gray titanomagnetite with spinel lamellae. The dark gray grains are olivenite, surrounded by hornblende. Nic //, Obj. 20x, air, 100 µm bar:
Same with Nic +:
The picture above already shows the presence of a third mineral as neither titanomagnetite or spinel are anisotrophic. Parallel to the spinel lamellae ilmentite lamellae can be found under higher magnification. Nic. //, Obj. 125x, oil.
The same with Nic. +:
For further informations on the region these articles might be interesting:
Ramdohr, P.: The ore minerals and their intergrowths. Pergamon Press, 1980
Sandecki, J.: Mineralogical and genetical aspects of the Smålands Taberg Fe-Ti-V ore, Protogine Zone of southern Sweden. GFF.122.(2000).351-358.