Solid inclusions

Zirconolite (Source C) [(Ca,Th,Ce)Zr(Ti,Nb)2O7]

Backscattered SEM image of "zirconolite" inclusion in sapphire from Source C

"Zirconolite" was found as a minor constituent enclosed in the marginal part of a large rough sapphire (Source C). It was intergrown with thorianite and surrounded by calcite and green spinel. All of these minerals were part of a very minor relict of rock material which is completely enclosed within the large pale blue sapphire. Regarding the chemical composition of zirconolite (cf. nomenclature by Bayliss et al., 1989), a recently published review paper on the different worldwide occurrences may be consulted (Williams and Giere, 1996) .