268 J. MILNE CURRAN. 
on the zircon, and a dull cutting noise is made. When the 
writing diamond is gently rubbed on a real diamond, it (the 
writing diamond) does not “bite” but glances and slips off in 
every direction, no friction due to cutting being apparent, and 
the sound produced is metallic-like and sharp. 
It may be well to remember also that where zircons are found 
a considerable number of the stones are red, or some shade of red, 
and on heating, these coloured stones become white and remain 
white on cooling. Red or green diamonds are exceeding rare. 
These rough and ready tests will also distinguish between small 
and waterworn topaz and diamond—stones which also are con- 
fused by prospectors. 
Topaz.—Clear waterworn quartz pebbles are continually mis- 
taken for topaz. The simplest and most convenient test for a 
prospector is, when these stones are abundant, to break one and 
note the high and perfect polish on the flat cleavage faces of the 
topaz. Quartz of course never breaks to show lustrous flat cleavage 
faces, but rather with irregular curved surfaces not unlike the 
fracture of common bottle glass. 
When crystals are found it may be noted that the topaz is 
striated and grooved up and down along the length of the prism, - 
while quartz is striated across the prism. 
A splinter of topaz mounted after the fashion of a writing 
diamond will in a moment distinguish between topaz and quartz, 
the topaz scratching quartz with ease. 
Heavy solutions are now so easily procurable that they may be 
of service to miners. Klein’s solution of borotungstate of cadmium 
has a specific gravity of 3-28, therefore every gem with a lower 
specific gravity will float in this liquid. Ifa white beryl, a topa% 
a quartz and a diamond are placed in this liquid, the quartz and 
beryl will at once float, while the diamond and topax will sink. 
In Klein’s solution— 
will sink—diamond, sapphire, ruby, topaz, spinel, garnet, zircon. 
Wilk font | quartz, cairngorm, amethyst, moonstone, emeé d, 
beryl, aqua-marine. 
