was
made by Damelle in 1750. The rough topaz of Brazil is worth from two to
one hundred lire the kilogramme, according to colour and purity.
The
Saxony topaz is generally of a pale yellow ; some have considerable
brightness, but these are rare. It changes colour when warmed, then
becomes white, but when again cool it resumes its first tint. It is
found at Schnaknistein, in the valley of Daneberg. It has no value
unless it be very large and very beautiful. The Mexican topaz, which in
the two last centuries was called Indian topaz, is almost the same as
that of Saxony, only it is more varied in its tints.
There
is a fine, very clear Siberian topaz, in colour similar to the yellow
of the jonquil. Those which are of the aquamarine colour, and are very
common, ought not, according to the general opinion, to be reckoned
amongst topazes. These various kinds, when analysed, gave
