18K Gold Necklace with Opal and 1.75 Carat of Diamond
This late 1920s opal and
diamond necklace has seen more than one life, maybe many.
The central portion is
hand-made in platinum (as tested), with a scroll-designed frame in geometric
pattern and the surmount in crown design. Measuring 36 x 26.1 mm., it appears
to be from the period when Edwardian had been adapted to Art Deco.
On each side, it is
suspended by two bar links connected by geometric links, ending with three
small bezels. The entire item is all diamond-set with bright cutting and
The 83 diamonds are
old-cut, both single and full, weighing about 1.75 carats total, with average
quality of J-K color and VS clarity.
The center opal is of the
crystal black variety (solid opal), weighing about 6.00 carats, and is mounted
in an 18-karat yellow gold crown setting. I believe it probably took the place
of something else, because of the way it is undercut on the back to fit the
Photographing any opal
accurately is very difficult. This stone has vivid play of color, predominantly
red in broad flash pattern covering about 25%, and the remainder in smaller
pin-fire. It is accompanied by a report from Stone Group Laboratories
identifying it as natural black opal from Lightning Ridge, Australia.
On each end, the neck chain
consists of open oval bar links with twisted wire inset segments (tested as
platinum); these are followed by silver-plated curb link chain (added later),
making 22" length overall.
Various small repairs are
present but visible only from the side and back. The most noticeable is the
bezel-set diamond at 12:00, which has been reinforced from behind with a tube.
But this item is in very good condition for its age.
Marks are present in two
places. One is on the side at the top of the main portion, which I see as the
letters "P" and "D" connected by a long line.
The other is on the side of
one of the long bar links next to the main portion. It appears to be a similar
mark, followed by "950" and a leaning pentagon filled in with a
five-rayed star that divides it into fifths.
I've researched these marks, with no success. I've considered whether
the "PD" signifies palladium, but neither acid testing nor the age of
the item supports this conclusion. If anyone can shed some light on them, I
would be grateful to hear from you.