Zirkelite is an oxide mineral with formula: (Ca,Th,Ce)Zr(Ti,Nb)2O7. It occurs as well-formed fine sized isometric crystals. It is a black, brown or yellow mineral with a hardness of 5.5 and a specific gravity of 4.7.
Name and discovery
Zirkelite was first discovered in Brazil in 1895. It was named for German petrographer Ferdinand Zirkel (1838-1912).
Initial discovery was from the Jacupiranga carbonatite, Sao Paulo, Brazil. It is also found in Canada, Kazakhstan, Norway, Russia, South Africa, the United Kingdom, and the United States.
* Webmineral data
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