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 Post subject: Blue colour change garnets
PostPosted: Thu Mar 15, 2018 10:58 am 
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Just wanted to share, Im a big fan of garnets so I was pretty happy to get a small parcel of these recently.

Not very big, just over 1ct each.

Image

Image

in daylight, white led light, and incandescent


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 Post subject: Re: Blue colour change garnets
PostPosted: Thu Mar 15, 2018 5:09 pm 
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Those are TRULY nice - and a carat size is quite large for a blue garnet!


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 Post subject: Re: Blue colour change garnets
PostPosted: Thu Mar 15, 2018 10:30 pm 
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Impressive.
What light sources are you using?


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 Post subject: Re: Blue colour change garnets
PostPosted: Fri Mar 16, 2018 12:09 pm 
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thanks!

I have more but they are slightly greener.

Light sources were - daylight, white led light / fluorescent, and incandescent


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 Post subject: Re: Blue colour change garnets
PostPosted: Fri Mar 16, 2018 8:30 pm 
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Were you able to get the specs on the stones?
Refractive Index?
Inclusion scene?


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 Post subject: Re: Blue colour change garnets
PostPosted: Fri Mar 16, 2018 8:44 pm 
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Can you give us the dimensions?


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 Post subject: Re: Blue colour change garnets
PostPosted: Fri Mar 16, 2018 9:26 pm 
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The needle inclusions on the first stone are very diagnostic for garnet I think. I have a similar (though much more included) example.


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 Post subject: Re: Blue colour change garnets
PostPosted: Sat Mar 17, 2018 1:19 pm 
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Agree, the needle inclusions are pretty common in garnet. Coincidentally that one sold pretty quick.
Unfortunately no RI or Lab tests, brought from my source in Asia on my travels just last week. African origin, most likely Madagascar?

Ive managed to take pictures of the rest of the parcel now so Ill give dimensions also -

Image

1.28ct (from initial post)
6mm / 5mm / 5mm

Image

1.2ct
6.5mm / 5mm / 4mm

Image

1.08ct
6.5mm / 5mm / 3mm

Now the greener ones. Ive seen internet vendors advertise these as blue garnet, but to me if its not a proper blue its not blue. Am I right in my assumptions ? Im unsure why many dealers are selling this as blue.


This one is on the "bluer" side

Image

1.06ct
7mm / 5mm / 3mm

Image

1.15ct
6mm / 5mm / 4mm

Image

1.34ct
6mm / 5mm / 5mm


Now for some terrible photos of inclusions, I need a better macro lens. Or just A macro lens would do.

from the 1.28ct -
Image


1.2ct
Image

The Heart
Image

thanks for looking


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 Post subject: Re: Blue colour change garnets
PostPosted: Mon Apr 02, 2018 11:36 am 
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You have a background color change also!


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 Post subject: Re: Blue colour change garnets
PostPosted: Tue Apr 03, 2018 12:43 pm 
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75TURBO wrote:
You have a background color change also!


that's different lighting mate :roll:


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 Post subject: Re: Blue colour change garnets
PostPosted: Wed Apr 04, 2018 6:03 am 
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I understand 75Turbo's feeling. Under completely different lightings, everything is more or less color change, and then you come to question the reality of the color change character in a stone.
It would be interesting to get a picture of another stone, same basic color but NOT color change, close to one of these garnets, under these 3 lightings, so that we could appreciate how one of of the stones changes color and the other does not, even if the background changes too.


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 Post subject: Re: Blue colour change garnets
PostPosted: Wed Apr 04, 2018 9:39 am 
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This is a 100% blog standard issue with photographing cc stones. It really isn't suspicious or unusual. Messing around with the white balance to get the background color consistent isn't necessaroly going to reflect reality any better. There is a reason a lot of sellers just use photoshop to simulate the change.


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 Post subject: Re: Blue colour change garnets
PostPosted: Wed Apr 04, 2018 6:30 pm 
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Stephen Challener wrote:
This is a 100% bog standard issue with photographing cc stones. It really isn't suspicious or unusual. Messing around with the white balance to get the background color consistent isn't necessaroly going to reflect reality any better. There is a reason a lot of sellers just use photoshop to simulate the change.


Thank you Stephen, you've pretty much hit the nail on the head. Having taken tens of thousands of pictures of gems in my lifetime, adjusting white balance on the camera never changes the colour of the gem. As you correctly point out only the background gets lighter or darker.

Just for the record these pics were merely cropped and pasted in good old Microsoft Paint : )

Isi, understand what youre saying, Ill try and get some pics up tomorrow ;)


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 Post subject: Re: Blue colour change garnets
PostPosted: Thu Apr 05, 2018 6:03 am 
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2 pieces of garnet from BEKILY, MADAGASCAR


Attachments:
bekily02.jpg
bekily02.jpg [ 31.14 KiB | Viewed 374 times ]
bekily01.jpg
bekily01.jpg [ 40.77 KiB | Viewed 374 times ]
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 Post subject: Re: Blue colour change garnets
PostPosted: Thu Apr 05, 2018 7:15 am 
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Isi wrote:
I understand 75Turbo's feeling. Under completely different lightings, everything is more or less color change, and then you come to question the reality of the color change character in a stone.
It would be interesting to get a picture of another stone, same basic color but NOT color change, close to one of these garnets, under these 3 lightings, so that we could appreciate how one of of the stones changes color and the other does not, even if the background changes too.


Stephen Challener wrote:
This is a 100% bog standard issue with photographing cc stones. It really isn't suspicious or unusual. Messing around with the white balance to get the background color consistent isn't necessaroly going to reflect reality any better. There is a reason a lot of sellers just use photoshop to simulate the change.


As promised.

Initially I tried a purple garnet next to the blue, wrong choice obviously due to garnets tendency to "colour shift".

But you can see the difference between a supposed colour shift, and a real colour change with the blue garnet.

With the purple garnet there is no real visible colour shift to the eye, so that would rightly be questionable.


Image

Next I tried it with an orange zircon, which I know is inert colour wise -

Results as expected, very obvious colour change with the garnet, and the zircon stayed orange.

Image

Overall a worthwhile test :)


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