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 Post subject: green iolite?
PostPosted: Sun Jan 27, 2008 11:40 pm 
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I'm doing a bit of cross posting here. I am a newbie to gems in all aspects. I bought this gem off ebay it is suppose to be iolite. Please tell me what you all think.

Image
Image


The stone is 3.94ct
Size / mm. 11.9x9.9x5.6 mm.

I'm still waiting for the stone to come in. And thanks to everyone for all thoughts in this posting and the previous.

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 Post subject: Me thinks.....
PostPosted: Mon Jan 28, 2008 11:46 am 
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Me thinks you might have diopside instead......

Lyresa D


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PostPosted: Mon Jan 28, 2008 1:38 pm 
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I have written the seller asking how it was determined that the stones were iolite. "What tests were done?" I asked.
The reply was that they have no gem lab. His father told him and his father has 30 years of experience.

I wonder if there was a misunderstanding or mis-translation...could he have meant idocrase and not iolite? Although, the color of these stones is far GREENER than I would expect idocrase to be. Usually idocrase has a strong yellow component.
:?:


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PostPosted: Mon Jan 28, 2008 11:03 pm 
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I to wrote the seller also and posted the response in my previous(first) posting about this gem.

I searched for idocrase and I found some interesting stuff about it look at THIS

Anyway I'll have to wait a couple of weeks for the stone to come in. I've been reading how I could determine S.G. with the stuff I already have on hand. And I'll try and practice on some of the other larger stones I have. But I still may take it to a cert. Gemologiist, my only prob would be paying a chuck of money for something that may not be worth it. Wouldn't mind paying it if I could get some training on how to do it as well. But last time I asked they said no but were willing to charge me $80 to appraise this ring I found.

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PostPosted: Tue Jan 29, 2008 6:53 am 
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Ask for a gem identification only. That is normally cheaper than a full appraisal.

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PostPosted: Tue Jan 29, 2008 10:50 am 
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thanks I'll ask. If it becomes cheap enough I have a couple I"d like to get accurately ID.

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PostPosted: Tue Jan 29, 2008 12:26 pm 
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I've been giving the seller a little grief myself.
His latest email invites me to pay $20 for an identification.
If it is not iolite, he will refund my $20.
The only concern I would have is who is doing the identification....hopefully, not his father.


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PostPosted: Tue Jan 29, 2008 5:44 pm 
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Quote:
The only concern I would have is who is doing the identification....hopefully, not his father.



HAHAHA :lol:
I bet it is!

I would be very surprised if that really was a natural and untreated Iolite.

First: Iolite on Ebay and for that price is VERY rarely clean.

Second: It's GREEN!!

I can't say it looks like an Idocrase either... I have seen so many of them that I'll have a hard time counting them. And this one does definitly not look like ANY of them.

Guess it could be tourmaline or something, but what did the seller say about the origin, treatment and the rest of the info? And what was the price?
I can't tell why, but in some way I can't see a tourmaline in that stone either, but at least that would be much more likely than Idocrase or Iolite I think.

Sorry for asking more questions than answers :oops:

Johannes Orstadius

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PostPosted: Wed Jan 30, 2008 2:28 am 
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It seems I have a mystery. Here is the info from the auction page

Number of Gems =1 pc.
Approx Weight =3.94ct
Gem Type =100% Natural Iolite
Shape =Oval
Size / mm. =11.9x9.9x5.6 mm.
Color =Forest Green
Clarity =IF
Luster =Excellent
Origin =Africa
Treatment =Unheated / Untreated
Hardness =7.0-7.5

with a finale cost including shipping was $19.99 US

In my previous post I used the Dendritics calculator and the specifics from the stones auction here is what Dendritics guesses what it is.

Hiddenite
Fluorspar
Carborundum
Saussurite
Tourm/Grn
Tourm
Peridot/grn

I'll check and see what my local gemologist would charge to ID. Hopefully it would be affordable.

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PostPosted: Wed Jan 30, 2008 5:51 am 
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When I use the dendritic program with bulging pavilion and moderate sides and 50% table ( tried with calipers against the screen) and the dimensions and wt. given here, the specific gravity estimates to (2.654 - 3.148) or 2.901 ± 0.240. Iolite is 2.58- 2.66.

Obviously this is just for fun, but my bet would be on green tourmaline because of its closer Sp.Gr. and darn it just looks like it. Awaiting more info :) Maybe a new TV show "CSI San Francisco" ...
Another armchair gemologist wanabee

Jim


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PostPosted: Wed Jan 30, 2008 11:59 am 
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Thanks for the info! Yeah... I can't come up with something else more possible than tourmaline :?
You're doing the whole gemmologic society a favour if you succed to identify the stone :wink:

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PostPosted: Wed Jan 30, 2008 10:17 pm 
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I contacted my local cert. gemologist today. Fees cost $35 for ID and $85 for appraisel. I also have another out of area offer for ID. I know inquiring minds want to know. And as soon as we find out it will be posted here. But still have to deal with the hard part- the waiting (for arrival/ID/posting)

It was because I did buy this stone, and the fact I never heard of green iolite that lead me to this forum and site. Because I was searching if there was such a thing as green iolite. We shall see. (just really hope in isn't cut glass)


Thanks everybody and keep on guessing.

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 Post subject: Got the stone in
PostPosted: Tue Feb 05, 2008 12:55 am 
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Ok. I got the stone in today and I'm gonna send it out for ID. But while looking at it on the coffee table on an envelope. Table down
Image

My wife noticed that one edge of the oval had a red(purple)/grey tone to it that faded into green. The color stayed in position while spinning the stone. I tried the visual optics of holding it close to my eye and using a light. I see small double set of rainbows. I do see a clear image of the light source and a faint double image. Standard light looks green. LED light looks blue. When placed on writing I can clearly see the writing not doubled up but magnified a bit.

Any ideas??? :?

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 Post subject: good!
PostPosted: Wed Feb 06, 2008 1:47 pm 
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"When placed on writing I can clearly see the writing not doubled up but magnified a bit."

Try this test again, but view the writing through the stone from different angles. Try at least three different directions. Rotate the stone 30 degrees or so but leave your eye and the lettering at the same points. Then rotate it again another 30 degrees. Same one more time. At some point, I am guessing that you will see doubled lettering.

Your Hanneman test (the light-source/eyeball test) told you that likely this stone is doubly refractive. If this is true, your view of the writing should be doubled as well. Remember, a doubly refractive stone has an optic axis (or maybe two) that will show single refraction- in other words, there could be one or two directions (but not three) in which the letters won't show doubling.

I would be surprised if you can't see any doubling at all from three different directions. Do you have a loupe? If so, look into the stone at the facet junctions on the far side. Are they sharp, crisp, and single lines? Or do you see them as a bit blurry or doubled? Again, try rotating 30 degrees and check again. Then once more. Look through the stone at the far facet junctions each time.

A good gemologist will never guess at the identity of a stone. But my guess is tourmaline. :D

Do you have a zircon by chance? Do these same "look and then rotate 30 degree" tests with zircon. It will be fun! I promise you! If you don't have one, buy one. But not a green one- a blue one.

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 Post subject: UPDATE ON MYSTERY IOLITE
PostPosted: Sun Feb 17, 2008 4:20 pm 
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I was sent the famous mystery green iolite wannabe and have tested it with results as follows:
Here is a picture I took, not quite as enticing as the ones originally posted, but the original pictures more closely resemble the gem; it is very pretty:
Image
If you look closely at the pic above, in an east-west direction, you can notice what appears to be color zoning.
This becomes evident when immersed in benzyl benzoate and viewed with a Kruss Horizontal Scope at a simple 10X magnification:
Image
There is no evidence of coating. And, there is no twinning visible when viewed through crossed polars and immersed.
RI: 1.544-1.553 (determined with System Eickhorst GemLED refractometer)
Birefingence: .009
SG: 2.637 (Hydrostatic Weighing on Mettler CM200)
UV: Inert, LW and SW
Polariscope: Doubly Refractive, with (drum roll, please) interference colors visible from the side, revealing a bulls-eye interference figure.

Any guesses now?


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