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