254 J. MILNE CURRAN. 
The specific gravity of Bodalla turquoise is 2-67, it has a hard- 
ness of 5-5 to 6. The chemical composition of an average sample 
is :— 
* Analysis of Turquoise. 
H,O onignition  ... ae .- 21°000 
3 ae a ee = a O00 
CuO ... oe cos ee aie io 4400 
Al,O, see op gs ..- 36°236 
Fe,0; st a uals vie 21264 
Cad -s.. a vs ia is (So Oe 
an 8 Pee pas a sis seit SEQOO 
100-05 
In a closed tube this turquoise gives off water, decrepitates, 
and on further heating turns black. Alone it colours a Bunsen 
flame slightly green, and with hydrochloric acida vivid blue. The 
pure varieties are almost entirely soluble in hydrochloric acid, 
making a grass-green solution. 
It has been stated that the turquoise described loses its colour 
with age. This may have arisen from the fact that seams of tur- 
quoise are found at the mine altered to a white porcelain-like 
material. Some polished samples in my own collection, although 
exposed to a strong light for about two years, have not altered in 
colour. A sample of a fine bluish-green colour, cut and mounted 
as a brooch, has not altered in colour since cutting eighteen months 
ago. Ihave observed that the turquoise does alter somewhat 
immediately after being removed from the parent rock. This I 
attribute to a loss of water, for the gem loses weight as well as 
colour when placed in the cabinet. Once dried, as far as my 
experience goes, the colour then assumed is permanent.’ | 
1 Since my visit to Bodalla turquoise has been found in some other 
localities of this district. A record of turquoise being found here, has 
been eran 3 made by Mr. Card—Records Geol. Survey of N. S. Wales, 
Vol. tv. 
