Untitled

light. The color in such cases is due to organic pigment. As far
back as 1737 topaz of a greenish tint was mined in Saxony, the only
important locality in Europe producing this stone, and put on the
market. It was then called Schnecken topaz, from Schneckenstein,
where it was found. Decorations in the Green Vaults at Dresden
bear witness to the beauty of some of its stones.
So far the true topaz has been under discussion, 8 in hardness,
3.6 in specific gravity and lustre vitreous, but by far the greater
quantity in the market is simply metamorphosed citrine, or pale
yellow quartz, 7 in hardness, 2.65 in specific gravity. Of this, the
cairngorm, or smoky quartz, is abundant in Scotland, the pale yellow
in Saxony, the sherry-colored in Spain. Citrine also occurs
abundantly in Brazil. There is little in North America. Smoky
quartz, together with light blue, light green, white and salmoncolored
is found in Colorado; but none in great quantities. A remarkable
deposit disclosed itself in 1868 in Switzerland, Canton Uri,
near the Tiefen glacier. The largest of its large specimens is now
in the British Museum. Citrine quartz, in its natural yellow shades
or changed to orange brown by heat, is always passed off as topaz,
perhaps with qualifying prefix of Indian, Occidental, Bohemian,
Spanish. There is the true Indian topaz, of a saffron yellow color, in
Ceylon as in Brazil, but very rare. Spanish topaz is citrine of a deep
brownish yellow, while "golden" is sometimes applied to citrine as
well as the true Brazilian, though the latest designation for such in
this country is "sun." It is confusing to the amateur, and a re-
liable house should always be consulted if the true gem is desired;
it is rarely kept elsewhere than at places of the rank of Tiffany.
Considering that the true is worth ten times the false, which falls
to the level of amethyst, rose quartz, rock crystal, it is well to become
informed.
The average jeweler recognizes as topaz only the yellow stones
in their various shades from pale to reddish brown, but the blue, or
blue tinged with green, are very interesting. Usually it is a pale
shade, but a darker tint is found, called "Brazilian sapphire," also
applied to blue tourmaline. The pale, bluish green or greenish blue
is very similar to aquamarine, and one is often sold for the other,
but topaz is heavier. In pure methylene iodide topaz sinks, while
aquamarine floats. As yellow tinged with red or brown forms the
standard color, the stones most likely to be mistaken for topaz,
besides the citrine just mentioned, are yellow sapphire, called Oriental
topaz, yellow zircon, and hyacinth garnet, or essonite the
cinnamon-stone. Because of the long familiarity with this shade
of topaz, reddish brown, almost always quartz, and produced by heat,
it may be said to be the popular color. Few know any other, except
pale or golden yellow, which may be the true topaz, but more often
is citrine. The sale of blue or pink is so infrequent as to be negligible.
The faults of the topaz, lowering the value of the stone, are
impure color, fissures, turbidity, and cavities, either empty or filled
with liquid. In burning, topaz must be heated gradually, else it will
be fissured. There are several methods, but the best is to pack it in
61