1) Calcium mineral 2) Cubic mineral
Found on
https://www.crosswordclues.com/clue/zirkelite
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...
Found on
http://en.wikipedia.org/wiki/Zirkelite
No exact match found.
