The Amethyst 99
rays,
the pale stones lose their violet colour and become a dull grey. Some
deeply coloured amethysts from Maine change to a wine colour in
artificial light, thus becoming even more beautiful.
The
amethyst's best claims to perpetual popular appreciation are its
beauty of colour and its adaptability as an ornament to harmonise with
a costume colour scheme. In the development of woman's discrimination
in dress, she desires a jewel for every gown and ornaments for
afternoon as well as for night, and for special occasions. Tor fabrics
of pearl-grey, amethysts mounted in dull silver should be in high
favour.
A
good amethyst should be of a deep purple colour, perfectly transparent
and throughout uniform in hue. Amethysts are distinctly di-chroic; they
rank No. 7 in the Mohs scale of hardness; specific gravity is 2.6 to
2.7. The crystallisation of this quartz is in six-sided prisms
terminating in pyramids. Lustre vitreous; cleavage none or distinct;
fracture con-choidal, glassy. It is doubly refractive, the twin colours
being reddish and bluish purple. Amethysts are usually cut step, while
the finer specimens are cut brilliant.
