of
golden, and leek, colours. The ancients supposed that the powers of the
Topaz increased, and decreased, with with increase, and decrease of the
moon. The true Topaz seldom occurs of a large size, without defects. It
is not in vogue at the present day with jewellers, although fifty years
ago it was fashionable enough. The stone is derived principally from
the Brazils. It will become strongly electric by heat, friction, or
pressure ; retaining that condition, and remaining in it, for several
hours. The Emperor Hadrian is reported to have possessed a seal-ring of
Topaz, engraved with the lines—
" Natura deficit; Fortuna moratur ; Deus omnia oernit."
According to The Honest Jeweller—by a German writer of the seventeenth century—" when thrown into boiling water the Topaz at once deprives this of its heat."
The
true, or Brazilian Topaz is one of the few precious stones which
contain the element " fluorine." It may be regarded as a Silicate of
Alumina,—wherein a part of the Oxygen of the Silica is replaced by the
fluorine. The old Testament Topaz (Pit-doh) which formed a part of
Aaron's Breast-plate, was probably a " peridot." Also the element "
Vanadium " has been detected in the Brazilian Topaz. Powdered Topaz was
formerly kept in apothecaries' shops, and sold as an antidote to
madness. The Scotch Topaz is only a Yellow Quartz.
"
The Topaz," writes M. Pomet, 1712, " needs no other preparation for
medicine than to be ground with Rose-water on a Marble, in the same
manner as Hyacinth,
