due
in part to the total reflection of light from its internal faces when
the incident ray strikes at an angle of a little more than twenty-four
degrees. Colourless diamonds are richest in the flashing of prismatic
hues, while in some coloured specimens it is scarcely apparent; at the
same time by-waters, yellow-tinged stones, are sometimes more brilliant
in artificial light than are the colourless diamonds.
Diamonds
have a wide range of colour; most numerous are the whites, yellows, and
browns in a great variety of shades; then come the greens; red stones
of strong tints are very rare, as are also blue, which have been found
almost exclusively in India; other tints of occasional occurrence are
garnet, hyacinth, rose, peach-blossom, lilac, cinnamon, and brown;
black, milky, and opalescent diamonds are among the rarities. Diamonds
without tint or flaw are rare indeed and even most of the world's
famous diamonds have imperfections.
The origin of the diamond's name is the Greek word adamas, meaning unconquerable; from the same root spring our words adamant and adamantine.
The origin of the diamond, according to classical mythology, was its formation by Jupiter,
