Page:A treatise on diamonds and precious stones including their history Natural and commercial.djvu/147

This page has been validated.
TOPAZ.
111

with little hazard, and if the color produced happens to be fine, the price is much augmented[1],

THE RED TOPAZ.

This beautiful gem, which yery seldom occurs naturally, is of afine crimson color, tinged with a rich brown; it is extremely rare, and generally taken to bea variety of ruby, for which I have seen it offered for sale. Its price, from its scarcity, is quite capricious; it has an exquisite pleasing color, very different from the glare of the artificial pink topaz.

THE BLUE TOPAZ

Is also a beautiful gem, of a fine celestial blue color. It has occurred of considerable



    in common with the blue and yellow varieties of fluor; it also contains fluoric acid; which may be the cause of the change of color produced by heat.

  1. Many impositions are practised in forming pink topazes. See appendix.