64 
Simpson — Contrihutions to Mineralogy of W .A. 
frequently occurring lenses are often many metres in length, but 
seldom exceed 30 cm. in thickness. They are usually characterised 
by aliundant dark mica and numberless long-bladed crystals of 
kyanite lying at various angles closel\- parallel to the foliation, 
and showing out prominently on weathered surfaces. The pro- 
portion of kyanite in a specimen from a typical lens was found by 
crushing and floating in methylene iodide to be 15 per cent. In 
colour the mineral is white, pale grey or somewhat iron-stained. 
The smallest visible crystals measure aliout 5 x 1 x i mm., the 
largest 70 x 5 x 3 mm., a very common size, ib 20 x 2 x 1 mm. 
Under the microscope in fine grains they are seen to be colourless, 
with the typical cleavages, extinction angle, and refractive indices. 
iVattlc Flat iCullalla '). — Right miles north of the South Bin- 
dooii occurrence, and almost on the same line of strike, the writer 
recently found a kyanite-bearing schist in a hill on the west side 
of Wattle Flat, almost at the extreme head of the Chittering Brook, 
here called the Brockman River. This place is near the N.W. 
corner of f.oc. 805, three miles N.R. of Cullalla railway station. 
The rock is a coarse-grained l)iotite schist iiiterbedded with 
other more or less highly altered rocks of a gneissic character, 
and striking approximately north. The kyanite was found in two 
forms. First as distinct white or pale grey crystals, varying in 
size from 10 x 4 x 3 mm. to 60 x 15 x 10 mm., and having surfaces 
indented by crystals of biotitc. Some of these crystals are sohd 
kyanite and have the full density of 3.60, others have a low’er 
density down to 3.35, apparently due to inclusion of quartz and 
mica. Some crystals show evidence of repeated twinning on 
fOOlf. Quartz veins are small and rare, and in only one case was 
kyanite found associated with one. In this case large dense 
crystals were attached to the outside of the vein and included in 
a biotite parting in the vein. 
The second mode of occurrence is really a modification of the 
first. A number of granular white lenticular “eyes,” which were 
conspicuous in the schisc, were found on examination to consist 
of a mixture of quartz and kyanite. the former preponderating. 
typical one weighing five grammes was crushed and separated 
with methylene iodide. The returns were 60 per cent of quartz 
with typical optical properties and a density under 2.67*, and 38 
per cent of kyanite with density over 3.32 and of characteristic 
appearance under the microscope. The small remainder was 
biotite. A close examination of these “eyes” usually discloses a 
Fontainebleau structure, the predominant granular quartz being 
* The whole fraction under 2.67 contained over 96 per cent, of 
silica. The fraction over 3.32 contained 43 per cent, of silica and 
56 per cent, of alumina, indicating the presence of 89 per cent, of 
kyanite, with 10 per cent, of included quartz. 
