Rtmprox — Contrihniions to Mineralogy of W,A. 
59 
in the Annual Reports of the Geological Survey for 1919* ami 
1921f, but no published description is availal)le. 
The rocks are dark green to pale grey in color, and 
characteristically dotted with small flakes of red brown biotite. 
An agglomeratic structure is often distinctly visible. 
An analysis was made of a specimen from Barjar Hill near 
Noonkanbah homestead with the following results ; 
SiO^ 
Ah-O. 
Fe^O. 
FeO 
MnO 
MgO 
q 
g' 
q 
q 
52.45 
8.64 
5.48 
.94 
.13 
6.42 
2.01 .38 10.42 
H 2 O— 
PI 2 O + 
TiO^ 
CO 2 
P/)5 
FeS2 
SO 2 BaO Total 
D 
1.99 
2.89 
5.85 
nil 
1.58 
nil 
nil 1.19 100.37 
2.60 
Analyst, D. G. Murray. 
The high percentages of titanium and barium are remarkable. 
Washington, however, records a leiicitite from Bearpaw Peak, 
Montana, with 0.50 per cent of BaO. A thin section of this rock 
reveals the fact that idiomorphic leucite is the most abundant 
constituent. The rounded or octagonal crystals vary from 0.03 
to 0.50 mm. in diameter, and the larger ones show numerous 
dusty inclusions arranged either concentrically or radially. Be- 
tween crossed nicols the larger crystals are flecked with small 
areas which are faintly birefringent. 
The associated minerals are finely divided chlorite, innumer- 
able small needles of rutile, small prisms of apatite and irregu- 
larly scattered flakes of biotite larger than the largest leucite. 
In the rock from “B.E.” Plill. the leucite is not so plentiful, 
and is in larger grains up to 1mm. in diameter, and the inclusions 
are not so regularly arranged. There is more biotite present, and 
a consideraijle proportion of a titaniferous augite, with yellow to 
violet pleochroism. In this rock, too, the larger augite and 
biotite individuals usually enclose several crystals of leucite. 
This is the only district in West Australia from which leucite 
has been recorded. 
(3). Ferrimoly'bdite, Mulgine, S.W. I)iv. 
Ferrimolybdite is preferable to molybdite as a name for the 
natural hydrated molybdate of iron, as most text-books give 
entirely misleading descriptions of “molybdite” based not on the 
* A.R.G.S.W.A., 1919, p. 42. According to J. E. Wells the locality 
given as Mt. Eliza should be Mt. North. This rock contains K 2 O, 
7.50 per cent. ; Na20, 0.68 per cent. 
