Any chance it is Natural Alexandrite

[Alex_Paul]

I have the gemstone that, I believe, can be :
1) Just Chrysoberyl ;
2) Natural Alexandrite ;
3) Synthetic Alexandrite or Synthetic Chrysoberyl ;
4) Or even Glass.

The density of the stone is approximately 3.75 (so it can't be corundum ?).
Under day light it clearly shows 2 colors : Green (90%) and Blue (up to 'dark blue' under some angles).
When I looked at it under candle light - it shows some parts (along the facets) as purplish , the rest of it still green.

For some reason the photo under day and photo light shows rather light blue, but in reality it is dark green.
Please find the images attached, sorry I was not able to take pictures under candle light.

Would be grateful for any opinion.

Thanks,
Alex

 

[Alex_Paul]

Just wanted to add that there is no bubbles under the loupe , but there are some dark spots, dots.

 

[Alex_Paul]

I think there is some answer which is too obvious . Let me guess - it is a Glass .

 

[arglthesheep]

Hi Alex,
whats the weight of the stone? (or size)?
In my opinion it seems to be some kind of glass.
Do you have an RI of the stone (refractive Index)?
Thanks

 

[Alex_Paul]

Thank you for your reply. I am afraid that the stone is too large for it to be alexandrite - it is
about 3 grams , or 15 ct (on the internet they say it is very unlikely to find alex of such size). I am not sure about RI, because I don't have the refractometer (do the local jewelers usually have it ?) but the density is approximately 3.75.
Also the color change is not very impressive (assuming I am measuring it correctly), under the day light it is dark green and under candle light - about half of the stone looks pale-raspberry. It doesn't glow at all under UV light. Under day light , when rotating the stone some smaller parts become blue or dark blue and are sparkling quite impressive.
Based on the information I found on the internet, they say when density matches (in this case the density is 3.75) it is some sort of synthetic imitation, can it be synthetic chrysoberyl. But I didn't see dark green chrysoberyls. So probably it is a glass with rare / matching density or not very good synthetic alexandrite ? RI will help to eliminate / confirm the glass and then if not glass have to figure out synthetic or not ?
Kind regards,
Alex

 

[LD]

My opinion is that it's definitely not Alexandrite or Chrysoberyl - sorry. There are certain clues ie colour, clarity, size, your description and the actual photograph itself. If it were an Alex you most definitely wouldn't have been able to take such a good photo of the daylight colour and taking a photo in incandescent/candle light would have been incredibly easy. As to what it is, I have no idea. My guess would be a synthetic of some description but an RI would help. I have a similar stone set into a 1920s Art Deco costume piece of jewellery and it's very pretty but it is glass (or paste I'm not sure which).

 

[Alex_Paul]

My opinion is that it's definitely not Alexandrite or Chrysoberyl - sorry. There are certain clues ie colour, clarity, size, your description and the actual photograph itself. If it were an Alex you most definitely wouldn't have been able to take such a good photo of the daylight colour and taking a photo in incandescent/candle light would have been incredibly easy. As to what it is, I have no idea. My guess would be a synthetic of some description but an RI would help. I have a similar stone set into a 1920s Art Deco costume piece of jewellery and it's very pretty but it is glass (or paste I'm not sure which).

Thank you for your reply. I think you are right , it is most likely some sort of synthetics.
The only thing I would add that the day light color is dark green only and is different from one on the photos (I guess in fact my digital photos show 2 colors - more central bluish ? and peripheral green).
I am attaching the "shades of green" image taken from the Internet - the day light color of the stone is closer to the left most on the image, or even darker (almost bottle green ?). If you begin rotating the stone it shows some blue and dark blue (different from bluish on the photos).
Thanks again,
Alex

 

[LD]

Actually it's not the colour it's the fact that you've been able to photograph the green at all. Unless you have expensive professional equipment it's almost impossible to take the green daylight photo and for the green (or blue green) to look like the colour you've managed to take. This is a big giveaway with natural Alex. Having said that - it's not impossible but it's always a red flag.

If you look at my photo below, these are all natural Alex and taken in daylight. You will see that none of them look particularly green. They look an odd colour - sort of grey/green and even with a touch of purple. These definitely do NOT look like these in real life! To my eye when taking the photo, the gem is green but on camera it very rarely shows!!!

 

[Alex_Paul]

Thank you. Yes, definitely my stone looks differently.
Also I made a couple of pictures attached under candle light and the stone didn't change the color, at least the most of it.

 

[arglthesheep]

Hi there,
as said from LD it is nearly impossible that this stone is an alexandrite. Size is a big problem as there are 15 ct alexandrites out there, but they are very rare and expensive. Your stone and color doesn´t really fit to alexandrite, but this doesn´t mean much as identifying a stone from a pic is mostly nearly impossible.
One possibility because of the plechocroism could be tourmaline but SG doesn´t fit. From SG it could be synthetic spinel for example, or probably glas.

 

[Alex_Paul]

Hi there,
as said from LD it is nearly impossible that this stone is an alexandrite. Size is a big problem as there are 15 ct alexandrites out there, but they are very rare and expensive. Your stone and color doesn´t really fit to alexandrite, but this doesn´t mean much as identifying a stone from a pic is mostly nearly impossible.
One possibility because of the plechocroism could be tourmaline but SG doesn´t fit. From SG it could be synthetic spinel for example, or probably glas.

Indeed , it looks very much similar to photos of synthetic spinel on the internet. Interesting if there is a chance that it could be the natural spinel, but it is very unlikely I guess. For some reason there are only synthetics on the web with similar dark green / bluish color.
Thanks again,
Alex

 

[arglthesheep]

Hi Alex,
natural spinel in green color is very rare, so I would say nearly impossible that this could be (again color and size). Also pleochroism wouldn´t match with natural spinel as it is SR. So my guess is dopped glass (rare earth).

 

[Bron357]

I’ll try again. This is Alexandrite under incandescent light vs daylight.

 

[kenny]

I’ll try again. This is Alexandrite under incandescent light vs daylight.

If the camera was properly white balanced to each light source used in each pic, the skin would be the same color in both.
The pic on the left is WAY more yellowish orange.
I doubt the model acquired liver disease, jaundice.
This means the color change of the gem in the pics is not believable.

(Kenny is just no fun anymore! )
I'm sorry.
I apologize for knowing about photography and spending 13 years trying to educate folks here.
I don't know why I bother.
Nobody listens and learns.
I must be so annoying.
I'm sure this post has insulted and pissed off many here.

Oh well, just shoot the messenger.

 

[Nosean]

I am sure you will have enough opportunities to teach us, Kenny!

Hundreds of boring glass or vanadium doped sapphire fake alexandrites will come - always the same questions, the same answers and pics...

 

[Alex_Paul]

I’ll try again. This is Alexandrite under incandescent light vs daylight.

Thank you for the comparing photographs, they help to figure it out the difference somehow.
Alex.

 

[Bron357]

If the camera was properly white balanced to each light source used in each pic, the skin would be the same color in both.
The pic on the left is WAY more yellowish orange.
I doubt the model acquired liver disease, jaundice.
This means the color change of the gem in the pics is not believable.

(Kenny is just no fun anymore! )
I'm sorry.
I apologize for knowing about photography and spending 13 years trying to educate folks here.
I don't know why I bother.
Nobody listens and learns.
I must be so annoying.
I'm sure this post has insulted and pissed off many here.

Oh well, just shoot the messenger.

Thanks Kenny. I’m the hand model with Jaundice.
While I appreciate your magnificent history with PS (26,000 plus comments and still going) your critique of my iPhone photos - in the kitchen under the kitchen exhaust fan, one with no lights on and the other with them on, is a tad savages. I don’t have a fancy camera, fancy lighting and computer software for post production enhancement and tone correction. Even if I did I wouldn’t be able to use it. I was merely trying to original poster show how artificial Incandescent light changes the colour.
Perhaps you will like these ones better, same basic iPhone photos (put gems in front of lens and press button) but no hand PLUS and a sapphire for reference. And I used a torch this time.
Though the most unbelievable thing about my little Alexandrite is that I paid the equilivent of $10 for it.

 

[minousbijoux]

Bron: don't be too concerned: those of us who have seen many alexandrites know that its just about impossible to capture on camera what your eye sees in real life. Sometimes it is necessary to allow the lighting (typically incandescent) to make our hands look jaundiced/washed out/strange in order to finally achieve something close to the true color you see in person. I completely understand, as I've had the same thing with one of my alex (photos are here somewhere).

 

[Bron357]

Bron: don't be too concerned: those of us who have seen many alexandrites know that its just about impossible to capture on camera what your eye sees in real life. Sometimes it is necessary to allow the lighting (typically incandescent) to make our hands look jaundiced/washed out/strange in order to finally achieve something close to the true color you see in person. I completely understand, as I've had the same thing with one of my alex (photos are here somewhere).

I’m fine, Kenny is a technical perfectionist and I don’t even have a “real” camera.
Yes Alex’s are chameleons, it’s easier to get the “purple” colour, but the daylight colour - I must have 30 photos and still none of them are the same let alone look like what my eye sees.

 

[Alex_Paul]

I am not sure if this is the good opportunity to ask this question - I read somewhere on the internet,
that there is a proven method (forgot its name) to find out if the stone is natural or not - by taking it close to the eye and looking through the stone at some light source, for ex. regular room lamp, and if you see multiple clear small rainbows (probably according to number of facets), then the stone is natural and not synthetic. I am not sure if this is correct / proven method and if it can be applied to all types of gemstones or not. Sorry again for the dilettante type question.
Thanks in advance,
Alex

 

[kenny]

When you see pics that are purported to document color change in a stone and both pics were taken with the same background but the backgrounds are not the same color in the two pics that means you cannot believe the color of the stone in the pics is accurately represented by the pics.
Some gems can change color, backgrounds and skin can't.

If you can't believe the color of the background, why would you believe the color of the gem?
The solution is to do a better white balance on your camera.
Some have a setting for, say, fluorescent light and another for, say, sunlight.
Of course these aren't too accurate because fluorescent comes in many 'colors' of white ... "warm" "cool" "daylight" etc.
Even sunlight itself gets more yellow as it passes at a lower angle through the atmosphere early and late in the day.
The most accurate white balance is doing it manually if your camera allows it.
Point camera at a large white or gray thing, light it with the light you'll take the pics with, and press the correct button to "tell" the camera that THAT is what NO color looks like under THAT light source.
Read your manual.

If your camera can't do that then don't use that camera for the types of photography that is is not equipped to do.
If you're going to take the pics anyway and the backgrounds in the resulting pics don't match either ignore be sure to "adjust" the color in your mind in the correct direction.
For example, if the skin is too yellow in one pic, you can be sure the stone was also moved in the yellow direction by the same amount.
So, imagine the stone less yellow.

Another approach is to use software (Photoshop or a cheaper alternative) to adjust the color of the backgrounds so they are both more true to life and they both match.
If the real background was white, make it white in both pics using the software.
If the real background was your skin, adjust the color so the skin in the pics matches your skin.

Nothing personal; not criticizing any person who posted any pics.
Just trying to be helpful and relevant on a forum where people judge colors in gems by posted pics.
I lament, but accept, that since the Kodak Brownie camera was introduced in February, 1900 all hope was lost of getting accurate pics when subjects present technical challenges.
No, I don't expect everyone to go buy $10,000 of camera gear.
But many things I teach can be applied to the simplest of cameras, some even to cameraphones.

Camera makers have convinced us you don't need to learn anything; just push one button and every pic will tell the truth.
It's unfortunate that the majority of us have fallen so hard for this lie.
It's also unfortunate when someone tries to educate they are seen as a jerk or a troll.

Skepticism and education is wise when it comes to photography, especially when spending lots of money based on color seen in pics.

 

[Alex_Paul]

Just wanted to add that my last question is not about the photography, but about some trick to figure out if the stone is natural or not.
Maybe somebody can share the secrets about how to determine if the gemstone is not synthetic,
w/out expensive lab tools (if this is possible at all with some degree of reliability).

 

[ringo865]

Bring it to a gemologist for testing.

 

[Alex_Paul]

Yes, that is true. This is probably the most rational solution.

 

[Alex_Paul]

Just in case , since everybody make photos of the stones under day light - please find attached 2 mine.
I hope it helps one way or another .

 

[minousbijoux]

Imo, definitely not. The colors to me make it look synthetic. As others have said, the only way to definitively know is to send it to a lab - posting photos here is not going to get you anywhere...

 

[Bron357]

Just wanted to add that my last question is not about the photography, but about some trick to figure out if the stone is natural or not.
Maybe somebody can share the secrets about how to determine if the gemstone is not synthetic,
w/out expensive lab tools (if this is possible at all with some degree of reliability).

Some gems are easy to pick as synthetic ie opal, others are harder. Synthetic sapphire is the exact same material as the real gem ie corrumdum but it’s man made. So it might need more sophisticated testing ie microscopic view of colour banding and flaws, but basically an all even colour throughout, a large size and no apparent natural flaws should make you think it’s synthetic.
Alexandrite is like emerald, it’s not a naturally “flawless gem”, though flawless / very clean examples do exist. So that can help identify a natural one, if you look at my Alex you can easily seen that it has lots of inclusions.
Your stone is very perfect and large size. That doesn’t automatically mean it’s a synthetic but it is should make you suspicious straight away.
And then, where / from whom did you buy it and how much did you pay?
The chances of someone unknowingly selling you a flawless 20 carat plus Alexandrite for a pittance, is so unlikely it isn’t believable (unfortunately).

 

[Alex_Paul]

Thank you for your reply. Yes, I agree with every point in your reply , this is most likely synthetic or the glass, it is too good to be true, to be the natural Alexandrite.
Thanks again,
Alex

 

[LD]

If the camera was properly white balanced to each light source used in each pic, the skin would be the same color in both.
The pic on the left is WAY more yellowish orange.
I doubt the model acquired liver disease, jaundice.
This means the color change of the gem in the pics is not believable.

(Kenny is just no fun anymore! )
I'm sorry.
I apologize for knowing about photography and spending 13 years trying to educate folks here.
I don't know why I bother.
Nobody listens and learns.
I must be so annoying.
I'm sure this post has insulted and pissed off many here.

Oh well, just shoot the messenger.

Kenny - you are right in everything you say apart from one thing. It is virtually impossible to photograph Alexandrites to show the correct colour change. It's an absolute phenomenon and not one that I've found with any other gemstone. David Weinberg (my guru on Alex) did explain it to me and even he said that to get a decent (but not wholly accurate) photo of both colourways, he has to photoshop - which of course is not something you really want to do! For the life of me I can't remember why Alex has this phenomenon and I'll try and find his explanation. In the meantime however, the only way of (perhaps) capturing the colour change using the same camera or phone is to take one photo during the day and in the same position at night with houselights on. This does however mean that the skintone makes you look like you've acquired jaudice on 12 hours! Funnily enough, seeing photos with the jaundice look actually helps me to identify if the Alex is natural or not!!!! You are absolutely 100% correct with regards to every other gemstone but not Alex I'm afraid. xxx (All of this is meant with respect and not at all pissed off!!!!!).

 

[LD]

Kenny - here's a photographer's forum regarding Alex. I think if you have a good camera and know how to use it (as you do), it may be possible to get a good and correct image but for us mere mortals it's more of a challenge https://www.photo.net/discuss/search/18817861/?q=alexandrite&o=date&c[node]=201