XLIII.
JADE.
A mineral substance very common in India and China.
It
is of an olive-green colour, but there is a particular kind of it
quite white, because destitute of the oxide of iron which renders jade
more or less a deep green, according as it exists in greater or less
quantity.
Its light is resinous ; it is very compact, and lasts longer than jasper.
White
jade is generally milky, opaque, and not very transparent. .Its
specific weight is of 2-9502 ; it is the hardest of all, and it more
particularly bears the name of Oriental jade.
The
nephrite or nephritic stone is a kind of jade which is found in Persia,
Egypt, Turkey, Poland, the Hartz, and in Switzerland, generally in
formless or rounded rocks. It is opaque, and its cleavage scaly ; its
specific weight is 3-3890.
In
New Zealand a species of jade is found, somewhat different from the
Oriental, as the colour is darker, and it has a specific weight of
2-2829.
America
produces jade somewhat inferior in quality, but, nevertheless,
tolerably hard. It undoubtedly falls from the mountains, as pebbles of
it are found here and there in the plains and fields.
Oriental jade always comes to us worked, and therefore, not being known in Europe in its rough state, it
