Page:A treatise on diamonds and precious stones including their history Natural and commercial.djvu/146

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110
TOPAZ.

ornament, and weighing nearly eighty carats was sold for £100.

Topazes have become more common since our intercourse with Brazil, consequently they are less in demand, and lower in price. A fine stone of sixty carats may be purchased at from £20 to £35; and smaller, calculated for ring stones, at from £2 to £5: but it is not usual to sell them by weight.

THE PINK TOPAZ.

Tue pink topaz is made from the yellow, which, when of intense color, is put into the bowl of a tobacco-pipe or small crucible, covered with ashes or sand: on the application of a low degree of heat, it changes its color from a yellow to a beautiful pink[1]. This is performed



  1. It possesses this property of changing color by heat