A) | 
OLIVINE-BEARING QUARTZ-MONZONITE FROM KIANDRA. 26 
the hornblende is of primary crystallization, separating out 
under conditions which rendered the pyroxene no lonzer 
stable. Dupare and Hornung’ have referred to hornblende 
produced in such circumstances as uralite, but J.A.Thom son” 
discussing what is evidently a very similar occurrence to 
that now being described, questions whether this term 
should be applied toa mineral whichisclearly primary. It 
seems to be largely a matter of the definition of the term 
“uralite,”’ and although the present writers cannot speak 
with much authority on the subject, from the examination 
of a few cases of what seemed to be uralitization it appeared 
that while for the most part there was pseudomorphism of 
the pyroxene by the fibrous amphibole in parallel growth, 
with concomitant formation of epidote, still there was 
also evidence of independent growth on the part of the 
hornblende. 
It would probably be safe to regard uralitization as at 
all events a post-consolidation process, and as the horn- 
blende in the present instance must have been formed 
when only about 70 per cent. of the rock was crystallized 
it may fairly be classed as primary. The hornblende all 
has the same appearance whether surrounding augite or 
clino-hypersthene, and is pleochroic in pale yellow-green, 
green, and pale bluish-green tints, the last suggesting the 
presence of a little of the glaucophane molecule, possibly 
due to absorption of some albite substance from the magma, 
Biotite is present in small crystals and grains, generally 
idiomorphic towards quartz and orthoclase, but moulded on 
the other minerals. It shows a strong tendency to attach 
itself to the peripheries of pyroxene grains, and very oftene 
has grown round a nucleus of ilmenite, other occasional 


* Comptes Kendus, 1904, p. 223. 
2 Geol. Surv. of West Austr., Bull. 33, 1909, p. 132; cf. also Teall, 
British Petrography, p. 95, and Williams, Bull. 28, U.S. Geol. Surv., p. 41. 
