TREATMENT AND CARE OF PEARLS 381
When
a pearl is cracked by a blow or by some accident, it is customary to
drill it at the end of the largest crack; this method prevents the
crack from extending in that direction. These fissures are sometimes
partly filled by means of a solution, and may not be visible at the
time when the pearl is bought, but they are liable to appear later.
To
illustrate the difference in the care used in drilling, we have
selected eight pearls from a paper of poor ones, and reproduce two
views of them, one to show the irregularity of the pearls, and the
other to show the varying size of the drill holes. Those on the left
were drilled by an artist, while those on the right show the work of an
inexperienced driller.
At
present pendant pearls are never drilled entirely through, and rarely
more than half way. But in the Orient, and even in Europe from the
fourteenth to the sixteenth century, they were often entirely pierced ;
even pear-shaped pearls were entirely drilled through, with a metal
edge projected below for safety. Frequently old pearls, and more
especially oriental pearls, have been entirely drilled through, as are
often large oriental rubies, diamonds, and sapphires. When these are
set, the holes are either plugged with pearl shell and polished smooth,
or a tiny ruby or diamond is set in a metal rim fitting entirely into
the drill hole or only slightly projecting. This is well instanced in
the portrait of Marguerite of France (1553-1615), in which the artist
Delpech shows all the pear-shaped pearls worn by the French queen
entirely pierced.
Frequently,
where pearls have been drilled by oriental workmen, the drill holes are
exceedingly large, five or six times the \vidth of the silk string; in
fact often from one to two millimeters in diameter. In the search to
supply the great demand, many oriental pearls have been secured which
formerly were strung to an oriental jewel by means of a thick wire ; it
is necessary to close this aperture, as the pearl would lie unevenly on
the string. This is done by introducing a mother-of-pearl plug, through
which a new drill hole is made. Unless the pearls are unstrung, this is
rarely visible ; but not infrequently the plug drops out. In other
cases the pearl has been drilled not only from end to end, but also
from the side, and this third hole is filled with a plug of
mother-of-pearl and polished over so as to hide the blemish from the
buyer. It is also no uncommon thing for a purchaser to find, after a
year, that cracks begin to develop where none apparently existed at the
time of his purchase, or they were so minute as to be considered of no
consequence.
One of the earliest references to drilling pearls was made by Ruge-rus, a monk who lived in the eleventh century. He says :
