ZIRCONOLITE 
Carbonatite. Carbonatites, with sixteen reported occurrences of 
zirconolite, seem to be the most common host rock type for this 
mineral. In the Kola Peninsula, Russia, zirconolite occurs in four 
separate carbonatite complexes where detailed descriptions, 
including studies on crystal morphology and crystal chemistry, 
is given in Bulakh & Ivanikov (1984). 
In the Afrikanda complex, Kola, zirconolite is described from 
the amphibolitized and fenitized pyroxenites (Borodin er al., 
1956) In Table 3 analyses C1—C3 are wet chemical analyses; 
Cl-C2 from Borodin et a/. (1956) and C3 from Bulakh et al. 
(1960). C4 is a microprobe analysis (Wark et al., 1973). 
At Vuoriyarvi, Kola, zirconolite was first described as zirkelite 
(Bulakh et a/., 1960), then *... tentatively described as a 
niobium variety, niobozirconolite’ (Borodin et a/., 1960). It is 
associated with apatite-magnetite rocks (accompanying 
carbonatites, Zhuravleva ef al., 1976), accumulating 
predominantly in apatite, and was also observed replacing 
hatchettolite (Kapustin, 1980). Analyses C5—C7 (Table 3) are 
unpublished wavelength-dispersive microprobe data (CTW) on 
separate grains (BM1970,39); C8—-Cll are wet chemical 
analyses: C8—C9 from Borodin et al. (1960), C8 and C11 quoted 
in Kapustin (1980); C10 is from Bulakh et al. (1960). 
Bulakh et al. (1960) refer to zirconolite from the Sayan 
Province, Russia. Analysis C12 (Table 3) is a wet chemical 
analysis from Bulakh et al. (1960). 
At Seblyavr, Kola, niobozirconolite was initially identified as 
zirkelite (Bulakh et a/., 1960) and is described as. . . the typical 
mineral of the process of amphibolization-dolomitization 
confined to carbonatite ...’ (Kapustin, 1980). The mineral is 
partly metamict, it has good symmetry habit and displays 
complicated twinning (Bulakh et a/., 1960). Associated minerals 
are apatite, clinohumite, tetraferriphlogopite, pyrrhotite and 
richterite. Analysis C13 (Table 3) is a wet chemical analysis from 
Bulakh et al. (1960). 
At Kovdor, Kola, zirconolite is associated with zones of 
carbonatization, Kapustin (1980). Cl14-C16 (Table 3) are wet 
chemical analyses: Cl14-C15 from Kapustin (1980), and C16 
from Kukharenko eft al. (1965). Analyses C17—-C34 are 
unpublished wavelength-dispersive micropobe data (CTW), on 
chemically-zoned zirconolite grains in a thin section of 
carbonatite. Associated minerals are baddeleyite and U-Ta-rich 
pyrochlore (Williams, in press). 
At Schryburt Lake, Ontario, Canada, zirconolite occurs 
intergrown with calzirtite, baddeleyite, and U-rich pyrochlore 
(Williams & Platt, in preparation). Microprobe analyses 
(C35—CS58, Table 3), show significant variations in PREE,O, 
and Nb,O;. Some of the grains have SREE** >50% of the Ca 
site, and, with Nd as the most abundant REE, this mineral can 
be classified as zirconolite-(Nd), following Bayliss & Levinson 
(1988), and subject to approval from the CNMMN. 
At Santiago Island, Cape Verde Republic, non-metamict 
Zirconolite-2M occasionally up to 2mm in diameter, occurs as an 
accessory mineral, often associated with pyrochlore, in 
apatite-rich s6vite, beforsite and glimmerite rocks of the 
Canafistula carbonatitic plug (Silva, 1979; Silva & Figueiredo, 
1980). Analysis C59 (Table 3) is the wavelength-dispersive 
microprobe analysis from Silva & Figueiredo (1980). 
At Phalaborwa, South Africa, zirconolite was first described 
by Verwoerd (1986) from the carbonatite. Analyses C60—C64 
(Table 3) are unpublished wavelength-dispersive microprobe 
analyses by CTW on sample BM1988,260, kindly provided by 
Prof. G. Bayer (ETH, Ziirich). In this rock, zirconolite is 
associated with baddeleyite and zircon, the latter mineral 
probably having crystallized at a later stage. Analyses C65—C66 
3 
are unpublished microprobe data (from Bochon University) 
from Prof. G. Bayer. 
At Sokh, Finland, zirconolite (reported as zirkelite) was 
originally described by Vartiainen (1980) from hydrothermal 
phoscorites. The crystals have apparently formed ‘... at the 
expense of pyrochlore and occur around and as inclusions in 
pyrochlore . . .’, and are also found as separate prisms. Analyses 
C67—-C70 (Table 3) are unpublished wavelength-dispersive 
microprobe data from Dr. I. Hornig-Kjarsgaard (pers. comm., 
1992), analysed at the University of Mainz. 
At Kaiserstuhl, Germany, zirconolite occurs with calzirtite, 
baddeleyite, Nb-perovskite and pyrochlore (Keller, 1984). 
Analyses C71 and C72 are wavelength-dispersive microprobe 
analyses (Keller, 1984; Sinclair & Eggleton, 1982). 
In the Hegau volcanic province, Germany, zirconolite 
(described as “Nb-zirconolite’) is a typical accessory mineral in 
the carbonatitic tuffs (Keller et a/., 1990). Analyses C73—C88 
(Table 3), are unpublished wavelength-dispersive microprobe 
analyses (CTW) of eight grains from a heavy mineral separate 
provided by Prof. J. Keller (Freiburg). 
At Prairie Lake, Ontario, Canada, niobian zirconolite is 
reported in association with wohlerite, pyrochlore, betafite and 
niobian perovskite (Mariano & Roeder, 1989). A microprobe 
analysis provided by Dr A.N. Mariano of six major elements is 
shown in Table 3 (C89). 
At the Cummins Range Carbonatite, Kimberley Area, 
Western Australia, accessory zirconolite occurs in an 
apatite-amphibolite rock. Qualitative analysis of the zirconolite 
showed the presence of Ca, Zr, Ti and minor Fe, but with Nb 
absent (Dr. A.N. Mariano, personal communication, 1993). 
At Howard Creek, British Columbia, Canada (Woolley, 1987; 
p.16), zirconolite is associated with zircon, magnetite and 
diopside in an apatite calcite carbonatite (Dr. A.N. Mariano, 
personal communication, 1993). There is no analytical data. 
At Catalao, Goias, Brazil (Woolley, 1987; p.179), zirconolite is 
associated with apatite and phlogopite in a calcite carbonatite 
(Dr. A.N. Mariano, personal communication, 1993). There is no 
analytical data. 
At Araxa, Minas Gerais, Brazil (Woolley, 1987; p.66), 
zirconolite occurs as prismatic crystals with anastase in a 
glimmerite, and also with pyrochlore, baddeleyite and apatite in 
a calcite carbonatite (Dr. A.N. Mariano, personal 
communication, 1993). There is no analytical data. 
Metasomatic Rocks. Zirconolite has been reported from 
metasomatic rocks at nine localities, although analyses from 
only seven of these have been published. 
In the Mt. Melbourne Volcanic Field, Victoria Land, 
Antarctica, zirconolite occurs as isolated grains with a 
maximum grain diameter of 0.08mm within ultra-potassic veins 
in a mantle xenolith from a basanite host (Hornig & Worner, 
1991). The major vein-forming minerals are leucite, plagioclase, 
nepheline, Mg-ilmenite, apatite and titaniferous mica. Analyses 
MI1-M7 (Table 3) are selected from Hornig & Worner (1991) as 
being the least ‘contaminated’ by adjacent silicate minerals. 
At the contact between granodiorite with gneisses and 
marbles in the Bergell aureole, Switzerland/Italy, chemically 
discontinuously-zoned zirconolite is observed, typically 
30—40um in diameter, associated with allanite and titanite, in a 
skarn (Gieré, 1986; Williams & Giere, 1988). The major minerals 
of the skarn are calcite, spinel, phlogopite and anorthite. The 
microprobe analyses M8—M22 (Table 3) are unpublished data 
(CTW) of eleven grains from three discrete zones, the averages 
of which are published in Williams & Gieré (1988). 
