The Sapphire 93
have
been seen that were blue at the ends and yellow in the middle. One
famous tri-coloured sapphire is cut into a figure of the Chinese sage,
Confucius; the head is colourless, the body pale blue, and the legs
yellow. Sapphires exhibit as many shades of blue as can be named. The
very darkest, almost black, is termed " inky "; pale " feminine "
stones are termed f water-sapphires "; dark, yet very blue stones, are
called " indigo-sapphires," " lynx-sapphire," or " cat-sapphire." The
tone and transparency of the stone are most important factors, and,
provided they are present, the very dark shades are not disadvantages,
although the " cornflower " is the choicest. Besides the " cornflower
" colour, tones and tints are indicated by such adjectives as "
Berlin," " smalt," " greyish," and " greenish." The dichroism of the
sapphire is nearly always apparent if the stone is viewed from an angle
that reveals it, the blue appearing tinged with green or with violet.
The dichroism of the sapphire is, like that of the ruby, taken into
account in producing the best effects in the cutting. In artificial
light some specimens remain unchanged, while others become darker, or,
perhaps, change to a reddish, purple, or violet colour. Asterias or
star-
