264 THE CURIOUS LORE OF PRECIOUS STONES
source,
and since then has had several revivals, until replaced by
black-stained chalcedony, the so-called onyx, and, later still, by
steel carved with glass and glass itself.
In
the sixteenth century jet was popularly called "black amber," and
Cardano states that in his time beads of this material were made up
into rosaries. He also says that curious figures made of jet were
brought from Spain to Italy.60
Many
are unaware of the fact that a number of ornamental objects made of
nephrite and jadeite—unquestionably of European origin—are to be seen
in the quiet little town of Perugia. These objects, collected
principally in central and southern Italy, constitute the Belucci
Collection, in that city. This collection also contains other specimens
of worked jadeite, which must have been brought to Europe at the time
of the Spanish conquest of Mexico and Peru. A very interesting example
shows us the utilization of a pagan celt to form a Christian emblem. By
the removal of a rectangular piece from each of the four corners of the
jadeite celt, a perfect cross has been made, the back and front of
which still offer the original polish given to the material centuries
ago by the native American worker. The superstitious belief propagated
in Europe by the returning Spanish sailors, very probably an invention
of their own to enhance the value of their jade and jadeite, that these
minerals were worn by the natives as a cure for diseases of the
kidneys, whence the name lapis nephriticus, rendered the
material exceptionally precious in the eyes of many, and quite possibly
it may have been thought that, by transforming this object into the
sacred form of the cross, a talisman would be produced that would not
only effect the
w Cardani, " De subtilitate," lib. v, Basilea?, 1560, p. 370.
