Fersmite
Formula: (Ca,Ce,Na)(Nb,Ta,Ti)2(O,OH,F)6
Mohs scale hardness: 4–4,5
Specific gravity: g/cm3
Rare earth elements: Ce
Rare earth content, %: REOmax=4,79 %
Other constituents, %: TiO2; Nb2O5; Ta2O5
Mineralklasse: Oxide, Niobates and Tantalates, MULTIPLE OXIDES CONTAINING NIOBIUM,TANTALUM OR TITANIUM
Uses:
References
https://en.wikipedia.org
http://rruff.info/doclib/hom/fersmite.pdf
http://www.mindat.org/min-1539.html
https://www.mineralienatlas.de/lexikon/index.php/MineralData?mineral=Fersmite