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Alexandrite or Color-change Sapphire?

Alexandrite or Color-change Sapphire?

vintagekaleidoscope
Thrill-Seeker
Hi, Lexy suggested maybe you could help me. I have a gorgeous ring that I am unsure of. I just bought a gemstone tester, and it registers as a sapphire. I understand both of these stones will do that though, so that is no help.

I cannot get deep teal color to photograph. It is an awesome color, I just can't capture it. I have included many pics...sorry if it is too many. :8}

This is the best I can get. The mark is K10 for 10k.

The stone is pretty big and it came from an estate sale. That is all I know about it.





















































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Schelly

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Message 1 of 25
24 REPLIES

Re: Alexandrite or Color-change Sapphire?

Re: Alexandrite or Color-change Sapphire?

in reply to Apr 21, 2010 2:50:32 PM
flanagan-laneantiques
Trailblazer
what you have is almost certainly a synthetic color change sapphire, also known as imitation alexandrite.
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Message 2 of 25

Re: Alexandrite or Color-change Sapphire?

Re: Alexandrite or Color-change Sapphire?

in reply to Apr 21, 2010 3:15:32 PM
vintagekaleidoscope
Thrill-Seeker
Thank you very much. How can you tell?
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Schelly

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Message 3 of 25

Re: Alexandrite or Color-change Sapphire?

Re: Alexandrite or Color-change Sapphire?

in reply to Apr 21, 2010 7:43:03 PM
elias11
Trailblazer
No one can tell from a picture, Flanagan is just offering an educated guess; that's all we can do here! By the way, the term "synthetic alexandrite" is often used as misnomer for "color change sapphire".

If your stone displays color change, you may have a color change sapphire (natural or synthetic, more likely synthetic), or you could have a synthetic alexandrite, or you could have an imitation, like color change glass.

I can tell you however, with a reasonable amount of certainty, that if the "big" stone that you describe displays a noticeable color change under different lighting conditions, it is probably NOT a natural alexandrite, which is almost impossible to find in this size, and which would not have been set in 10 karat gold.

Elias
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Message 4 of 25

Re: Alexandrite or Color-change Sapphire?

Re: Alexandrite or Color-change Sapphire?

in reply to Apr 21, 2010 8:18:24 PM
vintagekaleidoscope
Thrill-Seeker
Thank you, Elias.

I was wondering if it was worth an appraisal, but it sounds like it isn't.

I did find some other Victorian Alexandrite pieces on google that were set in 10K This does look older to me, but I am not sure how old.

I do know it isn't glass, because it registers as sapphire on my gemtester.

I don't know how to figure carat weight, but I would guess at least 2 carats.
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Schelly

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Message 5 of 25

Re: Alexandrite or Color-change Sapphire?

Re: Alexandrite or Color-change Sapphire?

in reply to Apr 21, 2010 9:22:46 PM
elias11
Trailblazer
If you can measure the diameter and the depth in millimeters, I can figure out the weight by formula, assuming it's a synthetic sapphire. From the pictures and relative to the mounting and the ring box, it looks more like four or five carats.

Elias
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Message 6 of 25

Re: Alexandrite or Color-change Sapphire?

Re: Alexandrite or Color-change Sapphire?

in reply to Apr 22, 2010 6:04:30 AM
allopapallo
Thrill-Seeker
From the cut, it looks modern.
I bet it is a man made color change sapphire, so many are sold on ebay as "alexandrite" but the name is deceiving.
Color-change corundum was grown around 100 years ago the first time, and used since then as an alexandrite simulant. A lot of "alexandrite" heirloom jewelry uses this corundum, that often contains vanadium to produce the color change.

Daniel

PS: I consider it a beautiful stone nonetheless and have used one as the center piece of a necklace. Personally, I like it better than natural amethyst. :-)
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Message 7 of 25

Re: Alexandrite or Color-change Sapphire?

Re: Alexandrite or Color-change Sapphire?

in reply to Apr 22, 2010 6:56:25 AM
vintagekaleidoscope
Thrill-Seeker
Elias, the best I can tell (not so good at mm measuring and measuring stones) it is 12 mm across and 6 or 7 mm deep.

Thank you, Daniel. The hallmark and ring setting look vintage to me, if not antique. Possibly just a streamlined 50s/60s rather than antique? I don't know very much about stones though.

It is quite pretty.
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Schelly

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Message 8 of 25

Re: Alexandrite or Color-change Sapphire?

Re: Alexandrite or Color-change Sapphire?

in reply to Apr 22, 2010 8:03:18 AM
vintagekaleidoscope
Thrill-Seeker
Measure another way it is 11mm across.
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Schelly

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Message 9 of 25

Re: Alexandrite or Color-change Sapphire?

Re: Alexandrite or Color-change Sapphire?

in reply to Apr 22, 2010 8:33:23 AM
elias11
Trailblazer
If the average diameter is 11.5mm, the depth is 6.5mm and the stone is a synthetic sapphire, it weighs a little over 6 carats (probably closer to 6.5 carats because the crown appears lumpy).

Elias
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Message 10 of 25

Re: Alexandrite or Color-change Sapphire?

Re: Alexandrite or Color-change Sapphire?

in reply to Apr 22, 2010 8:46:00 AM
vintagekaleidoscope
Thrill-Seeker
Thank you. That's a BIG stone.

So, I should just list as Color-Change Stone and list in description that I think it is color-change sapphire and likely synthetic?

This is all WAY over my head...
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Schelly

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Message 11 of 25

Re: Alexandrite or Color-change Sapphire?

Re: Alexandrite or Color-change Sapphire?

in reply to Apr 22, 2010 8:50:10 AM
elias11
Trailblazer
"So, I should just list as Color-Change Stone and list in description that I think it is color-change sapphire and likely synthetic?"

That would be perfect.. and you could add that the stone weighs approximately 6 carats.

Elias
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Message 12 of 25

Re: Alexandrite or Color-change Sapphire?

Re: Alexandrite or Color-change Sapphire?

in reply to Apr 22, 2010 8:53:37 AM
vintagekaleidoscope
Thrill-Seeker
Everyone, thank you so much for your help.

I was hoping a gemstone tester would make my listing easier...It did tell me this wasn't glass, but that is all it told me...
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Schelly

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Message 13 of 25

Re: Alexandrite or Color-change Sapphire?

Re: Alexandrite or Color-change Sapphire?

in reply to Apr 23, 2010 1:04:54 AM
elias11
Trailblazer
Everyone, thank you so much for your help.

I was hoping a gemstone tester would make my listing easier...It did tell me this wasn't glass, but that is all it told me...


Yes, these testers have limited capabilities.. and even if it could test differently for corundum (sapphire) and chrysoberyl (alexandrite), it would not indicate whether the stone is natural or synthetic.

Elias
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Message 14 of 25

Re: Alexandrite or Color-change Sapphire?

Re: Alexandrite or Color-change Sapphire?

in reply to Apr 24, 2010 9:26:07 PM
mc*opals
Trailblazer
LOL! good guess elias! You da man!


Just sitting back & watching. :-)

mc
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Message 15 of 25

Re: Alexandrite or Color-change Sapphire?

Re: Alexandrite or Color-change Sapphire?

in reply to Apr 24, 2010 11:24:34 PM
elias11
Trailblazer
Thanks MC!.. If you are referring to the weight, it wasn't a guess; I figured it by formula, using the measurements provided.

Elias
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Message 16 of 25

Re: Alexandrite or Color-change Sapphire?

Re: Alexandrite or Color-change Sapphire?

in reply to Apr 24, 2010 11:32:03 PM
winslow63
Scout
TIf you are referring to the weight, it wasn't a guess; I figured it by formula, using the measurements provided.


Yep, MC it's true, you just plug in the stone's measurements.

L x W x D (averaged if they're different when measured N/S and E/W

Here's a link to an online gem weight calculator.

http://dendritics.com/scales/carat-weight.asp

Now you, too can amaze friends and members here with your uncanny ability to estimate gem weight.

Wow! How does MC do it? They'll wonder...;-)
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Message 17 of 25

Re: Alexandrite or Color-change Sapphire?

Re: Alexandrite or Color-change Sapphire?

in reply to Apr 24, 2010 11:37:36 PM
winslow63
Scout
(averaged if they're different when measured N/S and E/W

Should read:

(averaged if they measure differently when measure N/S and E/W in round stones) Which is what Elias did for the stone above.
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Message 18 of 25

Re: Alexandrite or Color-change Sapphire?

Re: Alexandrite or Color-change Sapphire?

in reply to Apr 25, 2010 1:49:07 AM
elias11
Trailblazer
Of course, a gemologist does not need to use - and cannot depend on the accuracy of - an online gem calculator like the one in the link provided. Rather, he/she enters all the measurements/values individually in the formula, and makes adjustments according to the appearance of the stone, to arrive at a more accurate weight estimation.

Elias
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Message 19 of 25

Re: Alexandrite or Color-change Sapphire?

Re: Alexandrite or Color-change Sapphire?

in reply to Apr 25, 2010 7:46:36 AM
5starwatches
Enthusiast
Most likely your stone is synthetic corundum.
Alexandrite is a different mineral-chrysoberyl
and would never be set in 10k gold. Nice big Alexandrite can be $100,000.00 or more. I suggest you show your stone to gemologist.
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Message 20 of 25