yrope garnet), "spinel ruby" (more properly ruby
spinel), "Siam ruby" (very dark red corundum), "Ceylon ruby" (pale
pinkish corundum), rubellite (pink tourmaline), and lastly Burmah ruby
(the fine blood-red corundum).

While it is true that color, unless skillfully estimated and wisely used
in conjunction with other properties, is a most unreliable guide, yet
when thus used, it becomes a great help and serves sometimes to narrow
down the chase, at the start, to a very few species. To thus make use of
it requires an actual acquaintance with the various gem materials, in
their usual colors and shades and an eye trained to note and to remember
minute differences of tint and shade. The suggestions which follow as to
usual colors of mineral species must then be used only with discretion
and after much faithful study of many specimens of each of the species.

Let us begin with the beginning color of the visible spectrum, red, and
consider how a close study of shades of red can help in distinguishing
the various red stones from each other. In the first place we will
inquire what mineral species are likely to furnish us with red stones.
Omitting a number of rare minerals, we have (1) corundum ruby, (2)
garnet of various types, (3) zircon, (4) spinel, (5) tourmaline. These
five minerals are about the only common species which give us an
out-and-out red stone. Let us now consider the distinctions between the
reds of these different species. The red of the ruby, whether dark (Siam
type), blood red (Burmah type), or pale (Ceylon), is more pleasing
usually than the red of any of the other species. Viewed from the back
of the stone (by transmitted light) it is still pleasing. It may be
purplish, but is seldom orange red. Also, owing to the dichroism of the
ruby the red is variable according to the changing position of the
stone. It therefore has a certain life and variety not seen in any of
the others except perhaps in red tourmaline, which, however, does not
approach ruby in fineness of red color.

RED STONES OF SIMILAR SHADES. The garnet, on the other hand, when of
fire-red hue, is darker than any but the Siam ruby. It is also more
inclined to orange red or brownish red--and the latter is especially
true when the stone is seen against the light (by transmitted light).
Its color then resembles that of a solution of "iron" such as is given
as medicine. The so-called "almandine" garnets (those of purplish-red
tint) do not equal the