buncle.
Sapphire occurs in crystals, in rounded grains, and pebbles. It is
generally transparent, but sometimes only translucent, or displays a
shine of light of six rays, resembling the form of a star. It
possesses double refraction in a slight degree, and a vivid vitreous
lustre, which sometimes turns to that of mother of pearl. Its fracture
is from conchoidal to uneven. Its principal colors are blue and red,
with their various shadings; sometimes white, gray, yellow, green,
brownish-greeu, and black.
If
the red sapphire (ruby) is exposed to a great heat, it becomes green,
but when cold, returns to its original color; the green sapphire
undergoes no changes.
The various names given to sapphire, according to its color, are—
1st. Ruby (Oriental ruby), of a dark crimson red, cochineal or carmine, and rose-red, mostly inclining to violet-blue.
a. Oriental hyacinth, aurora-red.
2d.
Oriental amethyst, palish violet-blue; playing sometimes in rose and
purple red, like the common amethyst, except in its superior lustre.
3d. White sapphire, limpid and perfectly transparent; vivid lustre, resembling the diamond.
4
th. Sapphire, Oriental sapphire, from the darkest to the lightest blue,
with different shadings, whence it is denominated by different terms,
such as male sapphire, of a perfectly clear Berlin or smalts blue; female sapphire, full blue, with a tinge of white—sometimes sky-blue, with • streaks or specks; water sapphire, very pale-blue, and sometimes discolored; cat sapphire, blackish or greenish blue, often not transparent.
5th.
Oriental topaz; lightly yellow, lemon, or brownish straw yellow,
sometimes playing into green ; it is distinguished from the common or
true topaz by color and Ius-
