The
turquois is much used by Orientals to ornament their daggers, harness,
swords, and pipes. At one time there was much demand for these gems,
both in London and Paris, fine ring stones fetching as much as £10 to
£40 each. A perfect stone of the size of a shilling, and of good depth,
was stated to hare been sold for £100, but there does not appear to be
any fixed value for these gems.
The turquois is cut en cabochon on a leaden wheel and polished on a wooden one, and finished with rouge.
Odontolite or Fossil Turquois is
a name given to the bone remains of extinct animals, these being
coloured blue by phosphate of iron. They are brought from Siberia and
have a striking resemblance, when cut, to the true turquois. They
differ from it, however, by emitting an odour when gently heated, and
besides the organic structure is easily detected by the aid of a
microscope. "When the true turquois is dissolved in hydrochloric acid,
and ammonia added in excess, a blue coloured liquid results, showing
the presence of copper. The bone turquois being coloured by iron does
not give a blue colour when thus treated. Theophrastus mentions a
fossil ivory having variegated colours of white and blue which was
largely used by the jewellers of his time.
Turquois
is rarely found in Australia; fairly good specimens have, however,
been found at Hedi, King River, Victoria. The turquois from this
locality exists with or without quartz in veins running through a slate
rock. The colour of some portions is fairly good, but the veins are
often very thin. I have not been able to ascertain whether stones cut
from this turquois retain their colour, but a specimen from this
locality which has been in the Museum collection for a few years
appears to have perfectly retained its colour.
During
the year 1891 a discovery of turquois was made on Mount Lorigan, in the
Wagonga Division, Southern Miring District of New South Wales. At
present little information is obtainable as to the value of the find.
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