s shrouded
in mystery; they are, however, believed to have been found in one or
more of the islands in the Red Sea. In our day a number of specimens
have been discovered on the small island of St. John in that sea; the
deposit here is a jealously-guarded monopoly of the Egyptian
Government. Peridots have also been found at Spyrget Island, in the
Arabian Gulf. The most remarkable source of gem-material of this stone
is meteoric, a few gems weighing as much as a carat each having been
cut out of some yellowish-green peridot obtained by the writer from
the meteoric iron of Glorieta Mountain, New Mexico.

That a turquoise, presumably set in a ring, was given to Shylock by
Leah before their marriage, perhaps at their betrothal, is all that
Shakespeare has found occasion to write of this pretty stone, one of
the earliest used for adornment in the world's history, as the great
mines of Nishapur, in Persia, and those of the Sinai Peninsula were
worked at a very early time, the latter by the Egyptians as far back
as 4000 B.C. With the opal, the poet has seized upon its most
characteristic quality, its changeableness of hue, where he says in
_Twelfth Night_ (Act ii, sc. 4): "Thy mind is a very opal".

A luminous ring is poetically described in one of Shakespeare's
earliest plays, _Titus Andronicus_, written in or about 1590. The
lines referring to the ring are highly expressive. After the murder of
Bassianus, Martius searches in the depths of a dark pit for the dead
body, and suddenly cries out to his companion Quintus that he has
discovered the bloody corpse. As the interior of the pit is pitch
dark, Quintus can scarcely believe what he hears, and he asks Martius
how the latter could possibly see what he has described. The answer is
given in the following lines:

Upon his bloody finger he doth wear
A precious ring, that lightens all the hole,
Which, like a taper in some monument,
Doth shine upon the dead man's earthy cheeks,
And shows the ragged entrails of the pit.
_Titus Andronicus_, Act ii, sc. 3.
First Folio, "Tragedies", p. 38, col. B, lines 53-57.

This certainly was suggested by the common belief in naturally
luminous stones, a belief partly due to a superstitious explanation of
the ruddy brilliancy of rubies and garnets as resulting from a hidden
fire in the stone, and partly, perhaps, to the occasional observation
of the phenomena of phosphorescence or f