An older women has brought in a lovely old ring and stone that her
husband gave her before they were married. The ring needs reshanked
and at least one of the prongs needs retipping. The stone is a
8x12mm alexandrite. My problem is that I have had almost no
experience with man-made alexandrite and request any and all
guidance. Is it safe to retip the prongs with the stone in place or
must it be removed first.
mike weller
Mike,
Did you test the stone when you took it in for repair? If it is an
older ring from the 1960’s or earlier, it is most likely a Synthetic
Color Change Sapphire.
Over the years I have had many people bring these stones in to me
and say they were told that they were a Genuine Alexandrite.
It is best to clear up any misconceptions a customer has before they
leave something with you. This is good for you as well as the
customer.
With All Colored Gems I recommend that you remove it from the
setting to do the work unless you have a laser welder.
If you are not highly experienced the problem with heating a Genuine
Gemstone is with the inclusion such as liquid filled which can
expand and crack the stone. With a Synthetic Corundum there is less
chance of this happening but it is best to be safe since you would
have a terrible time trying to replace a Synthetic Color Change
Sapphire.
Good Luck
Greg DeMark
email: greg@demarkjewelry.com
Website: www.demarkjewelry.com
Custom Jewelry - Handmade Jewelry - Antique Jewelry
The chance that the stone is a man made alexandrite on that "old"
ring is pretty slight. I don’t believe a true synthetic alexandrite
was being produced until just a few years ago. All the stones I have
seen which the owner has referred to as alexandrite have actually
been synthetic color change sapphire. If you have the capability of
doing a quick R.I. on the stone you could clear that up in a hurry.
One giveaway however that the stone is synthetic corundum is that
instead of showing the green color alexandrite shows in day or
fluorescent light, it instead will show a blue or bluish gray color.
If it is corundum of course the heat should not bother it. All that
aside however, If the stone can be easily removed, then why not
remove it? If that’s a problem it would be prudent to pack the
stone inCool Jool or wet Kleenex or even do the water submersion
trick. (Never liked that one myself, but it works). Good luck.
Jerry in Kodiak
NO! NO! NO!!! Remove the stone.
Judy Shaw, GJG [GIA]
One giveaway however that the stone is synthetic corundum is that instead of showing the green color alexandrite shows in day or fluorescent light, it instead will show a blue or bluish gray color.
How dispositive is this?
The reason I ask is that I am still mourning the loss, almost 40
years ago, of a ring I recieved as a gift from my grandmother. It
was gold with an emerald-cut alexandrite of (I’m guessing from
memory) around 6-8 carats. It was very purple in one light, and
blue/grey/green in another. I always assumed it was a genuine stone,
hence the intensity of my grief that I carelessly lost it… uh,
plus sentimental value, of course… Actually, I adored that ring.
The stone absolutely fascinated me, and I can clearly remember the
cut and color, and gazing into its depths. This post makes it sound
as though it may not have been genuine after all. Is that the
general view? Thanks, all,
–Noel
Jerry in Kodiak, Greg DeMark, Judy Shaw
THANK YOU for your advise! I was digging through some my old books
and found where I had listed stone that are susceptible to heat
damage by hardness and alexandrite is FIRST on the list. I must be
getting old, I can’t remember writing it.
Again THANKS
mike weller
Mike, first be certain it’s a synthetic. this should be a “no
brainer” ID, but be sure. Among other things, i’ve seem some glass
products that at first glance seemed similar, which are more fragile
than the synthetic corundum (sapphire) common synthetic.
If the stone (unlikely for that size) is a true synthetic
alexandrite, then it deserves particular care since unlike the cheap
corundums, it’s a bit pricey and might be hard to replace. And it
likely will not respond well to retipping. just remove it for the
repair.
But for what you describe, it’s mostly likely the cheap corundum
product.
Either way, I’d not recommend retipping directly on the stone.
Corundum itself can take the heat, but you’d need to be very careful
to avoid contacting the stone with flux at soldering temps, as that
can etch corundum, and you’d need to use a torch flame that was
neutral to slightly oxidizng, again to avoid chemically altering the
aluminum oxide. It CAN be retipped, if you’re careful, but
understand that it’s a bit risky. These stones may be under some
strain, and even if you don’t damage it with flux or the heat, they
can crack. So you’d need to be very careful and gentle with slow
heating and cooling rates.l. Sometimes it’s possible to pull a
damaged prong away from the stone so there’s a millimeter gap between
the worn prong and the stone, which makes it then much simpler,
especially with a very tiny torch, to get some more metal on the tip
without overheating the stone. Be ready for the stone to
dramatically shift color during heating. don’t worry, when it cools,
it comes back.
But if you’re unsure of this, or don’t wish the risk of having to
spring for a new stone (probably cost you 25 bucks or less) if you
damage it, then just remove the thing. that’s the safest way to go
on a number of issues.
Peter
The chance that the stone is a man made alexandrite on that "old" ring is pretty slight.
Hi Jerry;
Actually, it’s most likely a synthetic. An 8 X 10 millimeter
Alexandrite of natural origin is something that people are not likely
to lose track of. They’ve never been common in such large sizes, and
would always have been very expensive. I do extensive work in
retoration of antique jewelry and these sythetic alexandrites were
quite common. I believe I’ve seen them in pieces dating from the
20’s. This was covered in a previous Orchid post, and many,
including myself, identified this material as doped man made
corundum. Best to remove the stone from the mounting before torch
work. Although it would likely withstand the heat of retipping, it’s
not worth the chance, since, although the stone has no great
intrinsic value, it could be hard to find a replacement.
David L. Huffman
Actually, it's most likely a synthetic....and many,including myself, identified this material as doped man made corundum.
The disagreement may be one of semantics. Synthetic alexandrite
would be alexandrite made in a lab. Doped corrundum would be an
alexandrite simulant. Now, if the doped corundum were being sold as
color-change sapphire, then it would be considered a synthetic.
Such is my understanding of the terms, anyway.
Lee Einer
Dos Manos Jewelry
http://www.dosmanosjewelry.com
Hi David,
If you have seen what you thought to be synthetic alexandrite in
pieces from the '20s or even the '50s you were seeing either
synthetic simulants, probably corundum, or natural alexandrite. As
you correctly state, it’s unlikely someone would lose track of a
stone as valuable as natural alexandrite has always been, so they
were probably the former. The first synthetic alexandrite was
produced, by the flux fusion process, in the early 1970s.
Jerry in Kodiak
Noel, it was ALMOST certainly SOME kind of man-made stone. I have
been a GG since 1983, and been in the wholesale and retail gem
business since then.
Many times, folks have brought in ‘heirloom’ alexandrites, and I have
NEVER in the 21 years found one which was a genuine Alexandrite of
any size over a carat.
You don’t have to feel guilty about losing your grandmother’s
’valuable’ gem.
Et ego te absolvo
David Barzilay
Lord of the Rings
607 S Hill St Ste 850
Los Angeles, CA 90014-1718
213-488-9157
All who possibly can, should once in their lifetimes observe a
genuine Alexandrite. There is truly nothing else like it and could
never be forgotten. Early in the discovery of those stones there
were quite large ones available. Probably all in vaults and
treasuries now, but I knew a woman who had a suite of them, necklace
ring and earrings, and saw them in all lights and conditions, and
found it most difficult to look at anything else in their presence.
Many years later I met a lady who had lucked onto a ring with at
least a 6x8mm stone in, at a yard sale in a shoebox of costume
jewelry. She knew it was something special, as did I on looking upon
it. Alexandrites do not look at all like the synthetic corundums.
The colors are quite different and they in no way look glassy. The
luster is rather a greasy one, deep and mysterious. Make an effort to
find one in museum or private collection. It would be memorable.
Patricia
The disagreement may be one of semantics. Synthetic alexandrite would be alexandrite made in a lab. Doped corrundum would be an alexandrite simulant. Now, if the doped corundum were being sold as color-change sapphire, then it would be considered a synthetic.
Lee, not semantic at all. One of the more challenging aspects of
gemological study is understanding the relationships between
synthetics, simulants and imitations. Your understanding is
flawless.
James in SoFl
Hello Orchidland, I beg to differ:
it's unlikely someone would lose track of a stone as valuable as natural alexandrite has always been,
My daughter worked in a fine custom jewelry store and told me of a
woman who brought in an old ring, which she had bought at a thrift
store. She saw the metal was marked as karat gold, but thought the
stone was a simulant. Turns out it was a very nice diamond, well over
a caret. I’d guess it was hidden in a drawer with clothes. The
owner died and when the house was cleaned out, the drawers were
dumped into boxes and the contents donated to charity.
People DO lose track of those small, but precious bits of jewelry…
especially folks whose memory may be failing. Which reminds me, I
wonder where I put that diamond ring I inherited from my mother…
do the kids even know it exists??? (That’s what I mean.)
Judy in Kansas
If you have seen what you thought to be synthetic alexandrite in pieces from the '20s or even the '50s you were seeing either synthetic simulants, probably corundum, or natural alexandrite.
Hi Jerry;
That’s exactly what I said, or meant to say if it wasn’t clear.
What I’ve seen, I’ve come to learn, are man made corundum, doped to
attain the color, somewhat, of alexandrite. Perhaps somebody here
know when those were first made.
David L. Huffman
The disagreement may be one of semantics.
Hi Lee;
Right . . . I’ve always confused that. Simulant is the word I was
looking for. It’s a synthetic corundum, that is, chemically a
corundum, but sythensized in a lab. If it’s meant to look as if it
were an alexandrite, it’s simulating an alexandrite, hence, a
simulant. Have I got that right?
David L. Huffman
David,
Actually a simulate or a synthetic can look like a genuine.
The difference is that a synthetic has all the same physical,
chemical and optical properties as the genuine that it is trying to
look like.
A simulate can only look like the gemstone it is trying to look
like.
There is also the synthetic that is a simulate. Such as a synthetic
Spinel trying to look like a Sapphire or Ruby.
Greg DeMark
email: greg@demarkjewelry.com
Website: www.demarkjewelry.com
Custom Jewelry - Handmade Jewelry - Antique Jewelry
It's a synthetic corundum, that is, chemically a corundum, but sythensized in a lab. If it's meant to look as if it were an alexandrite, it's simulating an alexandrite, hence, a simulant. Have I got that right?
To the best of my knowledge, you are right on the nose, David.
Synthetics are lab-created versions of the naturally occuring gem,
while simulants ape the appearance of the natural gem but are
composed of a different material.
Thus, a lab-created corundum is a synthetic sapphire (or ruby,
depending on color) but when used to impersonate an alexandrite, it
is an alexandrite simulant, not a synthetic alexandrite.
Lee Einer
Dos Manos Jewelry
http://www.dosmanosjewelry.com