COLOR AND FLAWS 141
when
faced up to the eye. In others it appears deeper when viewed edgewise
than in any other direction. Occasionally the poorest color appears in
the face of the stone, but this is seldom the case, as cutters and
cleavers naturally try to arrange their work so that the best will come
to the front in the finished product.
The
cutting of a stone has its influence on the apparent color. One that
is cut shallow will not appear to have as much as it really has. A
thickly cut stone makes it more perceptible. If the body of a stone is
white and the culet is cut in a bit of color, that will appear
throughout the stone when it is faced up.: Oriental cutters take
advantage of this in the cutting of rubies and sapphires especially, by
placing the culet in a stratum of good color, even if they must spoil
the shape of the stone to do so. Diamonds are not affected thus to the
same degree, because they seldom have strata of decided color and when
they do, the tints are so weak that the differences are not easily
distinguished, though the result is noticeable as an uncertain color
which varies with the changes of light and position in which it is
seen. These are the false color stones. Most of them appear blue with a
tendency to violet under a strong natural light, the tint becoming
stronger and therefore better as the stone approaches the eye. Uusually
the blue shows to best advantage under a loup with an inch focus,
though one experienced, by moving the stone to different angles, will
catch fugitive glimpses of the deteriorating hues included. These are
generally yellow, sometimes brown. Upon removing these stones from the
clear sunlight to a mixed or artificial light, the inferior colors
become dominant.
