mineral and in the different minerals. There is dichroism in the
cases of pink sapphire, pink tourmaline (strong), pink topaz (strong),
pink beryl (less pronounced), and kunzite (very marked and with a
yellowish tint in some directions that contrasts with the beautiful
violet tint in another direction in the crystal). Pink quartz is almost
always milky, and shows little dichroism. Pink spinel is without
dichroism, being singly refracting. Hardness and specific gravity tests
will best serve to distinguish pink stones from each other. The color
alone is not a safe guide.

PURPLE STONES. Among the mineral species that furnish purple stones, (1)
quartz is pre-eminent in the fineness of the purple color. Such purple
stones are, of course, known as amethysts. After quartz come (2)
corundum (Oriental amethyst), (3) spinel (almandine spinel), (4) garnet
(almandine), and (5) spodumene (variety kunzite).

The purple of the amethyst varies from the palest tints to the full rich
velvety grape-purple of the so-called Siberian amethysts. The latter are
of a reddish purple (sometimes almost red) by artificial light, but of a
fine violet by daylight. No other purple stone approaches them in
fineness of coloring, so that here we have a real distinction based on
color alone. If the purple is paler, however, one cannot be sure of the
mineral by its color. Purple corundum (Oriental amethyst) is seldom as
fine in color as ordinary amethyst, and never as fine as the best
amethyst. It is usually of a redder purple, and by artificial light is
almost ruby-like in its color.

Purple spinels are singly refracting, and lack dichroism, and hence lack
variety of color. Almandine garnets also show no dichroism and lack
variety of color. The garnets are, as a rule, apt to be more dense in
color than the spinels.

Purple spodumene (kunzite) is pinkish to lilac in shade--usually pale,
unless in large masses, and it shows very marked dichroism. A yellowish
cast of color may be seen in certain directions in it also, which will
aid in distinguishing it from other purple stones.

BROWN STONES. (1) Diamond, (2) garnet, (3) tourmaline, and (4) zircon
furnish the principal brown stones.

Diamond, when brown, unless of a deep and pleasing color, is very
undesirable, as it absorbs much light, and appears dirty by daylight and
dark and sleepy by artificial light. When of a fine golden brown a
diamond may have considerable value as a "fancy" stone. Such "go