PRECIOUS STONES. 135
2x2x8,
or £82 while one of three carats would be 3 X 3 X 8, or £72; this
however gave too high a value even at the time it was introduced ; in
1869 when a rough Diamond of one carat was worth about £5, Schrauf
suggested another rule by which the value in pounds would be found by
dividing the weight in carats by two, and multiplying this dividend by
the weight in carats plus two, and by the value of a stone of one
carat. Thus, if a stone of one carat were worth £12 cut, a stone of the
same quality, but weighing two carats, would be worth 1/2 (2 + 2) x
£12, or £48. A rose-cut stone of the "first water" is worth about
four-fifths as much as a brilliant-cut one of the same quality. First
water stones are those which are perfect; those of the "second water"
are such as only show slight imperfection—either flawless, but tinged
with colour, or colourless, but with slight flaws. " Third water "
stones show more marked flaws, or departure from the colourless ideal.
" Fancy stones " are those of marked and beautiful colour, and such
cannot be valued by any rule. A brilliant of the second water is worth
about two-thirds as much as one of the first water, but a rose-cut
stone of the second water does not differ so much from one of the first
water. With the increased production these values are not very
reliable, and smaller stones of all but the first water only increase
in value in direct proportion to their weight. A first water stone of
one carat cut as a brilliant may now bring £15 to £25.
Counterfeiting and Recognition.
The Diamond may be imitated by other colourless gems, as Topaz, Corundum, Spinel, Quartz, Phena.kite, or Tourmaline,
