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 Post subject: Scapolite with unusual fluorescence?
PostPosted: Wed Jan 13, 2021 10:47 am 
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I have a ring from one of the defunct tv channels (no laughing :D ) - it even has the laminated paper credit card size certificate :lol:

The stone is reported as a scapolite from Madagascar, and I know the tv channel stuff is just marketing hype but the stones usually do seem to be as specified. I was doing some basic checks out of interest as it's my first time handling a scapolite and found something I couldn't find any information on. Under shortwave UV it goes a deep green - like a chrome diopside deep green and that didn't seem to fit with the normal definitions.

The stone is transparent sugary golden brown tone. I can't see any inclusions with a loupe. It is doubly refractive. The thermal meter is inconclusive putting it in the area where it could be any number of stones. Pleochroism is very weak. It is pretty much inert to longwave UV but goes deep green under the shortwave. I read some scapolite could have uranium oxide in it but I would have thought this would give an acid green/yellow colour and shouldn't it also then fluoresce in the longwave?

It's just for my general interest really but has anyone else come across this, or could it be something other than scapolite?


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 Post subject: Re: Scapolite with unusual fluorescence?
PostPosted: Wed Jan 13, 2021 11:26 am 
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Do you have

Refractive Index,

Birefringence,

Optic Character,

Specific Gravity,

Pleochroism.

There is a reason that these are the core of gem identification data.


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 Post subject: Re: Scapolite with unusual fluorescence?
PostPosted: Wed Jan 13, 2021 12:08 pm 
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1bwana1 wrote:
Do you have
...
RI - I don't have a refractometer yet - the way this stone is mounted I probably couldn't get a reading anyway.
OC - it is doubly refractive.
SG - It's set in gold
Pleochroism - very weak of same tone as body

As I mentioned it is unlikely the stone isn't what says on the report card, the larger tv companies had a lot of scrutiny on their offerings, it's not like the etsy/ebay free for all from India an China. I was interested in the unusual SW UV response which I couldn't find anywhere.


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 Post subject: Re: Scapolite with unusual fluorescence?
PostPosted: Wed Jan 13, 2021 2:08 pm 
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Is the stone in a setting to fragile or complicated to remove and reset? I know you stated it is just your curiousity, but it seems you would want to positively I'd the stone. I also imagine your going to resale or is it just a piece you plan to keep?

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 Post subject: Re: Scapolite with unusual fluorescence?
PostPosted: Wed Jan 13, 2021 2:58 pm 
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Sounds like a job for a Raman Spectrometer to me.


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 Post subject: Re: Scapolite with unusual fluorescence?
PostPosted: Wed Jan 13, 2021 8:12 pm 
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Based on your description it doesn't sound like it would be a scapolite. Scapolite usually has a fairly distinct pleochroism (Yellow colours usually have a almost colourless and yellow dichroism) and I haven't known any Scapolites to go green under UV. I do know of a few other stones that can be yellow and go green but without further testing I wouldn't be able to narrow it down much. On top of the previous questions posed I'll ask a few more:

Do you have a B/D ratio using Visual Optics?
Do you have a polariscope/conoscope that you can try to find the optic axis and get an optic character?
Do you have any colour filters? (CCF or Hanneman/Hodgkinson)
Do you have a spectroscope that you can see if it has any absorption spectrum?

In the end, I don't think you have a scapolite based on your description but barring sending/bringing it to a lab you would need more information before we could try and point you in the direction of what it might be or to truly confirm if you have scapolite or not.

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 Post subject: Re: Scapolite with unusual fluorescence?
PostPosted: Thu Jan 14, 2021 9:51 am 
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glhays wrote:
Is the stone in a setting to fragile or complicated to remove and reset?

It's not too bad, although I do plan on reselling at some point, so I would rather not. As it is I don't have the equipment to do further checks anyway, I would take it to my 'go to' guy but lockdown. It's not an expensive item by any stretch so I'll just keep it until I have chance to find out more.

S. Rautiainen wrote:
Do you have a B/D ratio using Visual Optics?

Thanks, this is something I need to read up on. The other items you mention I don't have currently, I have only recently started to sell some jewellery (I'm an antique dealer) and I have been sticking to easier items like diamond, ruby and sapphire. I have started to pick up a few more interesting items out of curiosity if I like them. I do plan on buying equipment and learning to use it properly but I want take time to assess which will be most useful. For example all the pieces I buy are set, sometimes scratched, little chips etc making things a bit more difficult. If I can't be sure what the item is I'm just keeping it for now until I can learn more, or the lockdown ends.

1bwana1 wrote:
Sounds like a job for a Raman Spectrometer to me.

Would be great, unfortunately I don't know anyone who has one!


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 Post subject: Re: Scapolite with unusual fluorescence?
PostPosted: Thu Jan 14, 2021 2:47 pm 
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Just FYI to this post, we pulled a tray of our Scapolite gemstones and parcels of rough, none of it exhibits what you are describing. Sending your ring for gem identification is not barred by any lock down order. I do not think a couple of the members here who have invested in the proper tools for this type of situation, charge all that much.

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 Post subject: Re: Scapolite with unusual fluorescence?
PostPosted: Fri Jan 15, 2021 8:06 am 
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C Elwell wrote:
The other items you mention I don't have currently, I have only recently started to sell some jewellery (I'm an antique dealer) and I have been sticking to easier items like diamond, ruby and sapphire. I have started to pick up a few more interesting items out of curiosity if I like them. I do plan on buying equipment and learning to use it properly but I want take time to assess which will be most useful. For example all the pieces I buy are set, sometimes scratched, little chips etc making things a bit more difficult. If I can't be sure what the item is I'm just keeping it for now until I can learn more, or the lockdown ends.


All of the things I asked if you had can be used on a mounted piece. They're part of the go to set of tools that I use whenever I try and appraise stones that I don't know what they are in my business. If you wanted, you could make your own polariscope and conoscope from (almost) any pair of sunglasses and a little maple syrup. There's a great book by Dr. Hanneman called Guide To Affordable Gemology that has a few ways of improvising or making your own tools until you want to start buying more professional ones.

As was mentioned, no lockdown prevents mail from what I know either. You could send it to your 'go to' person if you were in need of identification quickly but it's up to you if you need it done quickly or not. If you have other questions of course just post them. Good luck

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 Post subject: Re: Scapolite with unusual fluorescence?
PostPosted: Fri Jan 15, 2021 2:27 pm 
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I'd be interested to know if your scapolite is tenebrescent.
When you turn off the swuv does it still glow?
Tenebrescence is common with scapolite and the color is often a darker blue.


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 Post subject: Re: Scapolite with unusual fluorescence?
PostPosted: Fri Jan 15, 2021 3:30 pm 
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glhays wrote:
Just FYI to this post, we pulled a tray of our Scapolite gemstones
Many thanks for checking, very kind of you.

S. Rautiainen wrote:
All of the things I asked if you had can be used on a mounted piece
Thank you, those will be foremost on my list. I do have (actually wife has) polarisers, but I'm guessing they would need to be linear for this (hers are circular type for photography).

S. Rautiainen wrote:
As was mentioned, no lockdown prevents mail from what I know either
Yes, you are quire right, I normally trade stock with him at the same time and appraise glass and other items for him so take a batch of items when I do. It's only a cheap item and I will hold onto it for a while as it will be interesting to practice on when I stop dithering about which equipment to buy first! When I do see him next, hopefully in early March I'll post results if I remember.

Barbra Voltaire, FGG wrote:
I'd be interested to know if your scapolite is tenebrescent
I learned a new word today, thank you. I took it into my wife's photography room in blackout (neutral walls) and tried again. Still looks inert in LW, still quite strong green in SW but perhaps not as deep a green as when I first checked, like a deep emerald this time. I kept the SW light on for 15 mins, didn't notice any change afterwards, and no, there is no glow or phosphorescence once the light is switched off. I would leave it in the sun for a day to try the tenebrescence, but it's January in North East UK so may be weeks before that is a possibility :roll:

As a side note, while I was doing this I noticed a piece of Lalique glass in the room (clear glass not opalescent) glowed a very attractive sky blue under the SW UV - would this be from the lead oxide?

And a humourous take-out, when I searched for tenebrescence the first result was for incontinence wear!


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 Post subject: Re: Scapolite with unusual fluorescence?
PostPosted: Fri Jan 15, 2021 3:46 pm 
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Sidebar: I wrote a wee article on tenebrescence some time ago. By wee, I mean small, not incontinent.
https://gemologyonline.com/hackmanite.html

Sidebar #2. Fluorescent leaded glass:
https://www.cooperhewitt.org/2019/04/09 ... cut-glass/

Sidebar #3. Tonic water fluoresces too. If you order a gin and tonic or vodka tonic, etc., it will glow under fluorescent light.


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 Post subject: Re: Scapolite with unusual fluorescence?
PostPosted: Fri Jan 15, 2021 4:35 pm 
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Barbra Voltaire, FGG wrote:
I'd be interested to know if your scapolite is tenebrescent.
When you turn off the swuv does it still glow?
Tenebrescence is common with scapolite and the color is often a darker blue.

Would that support possible irradiation? And why green? Would be nice to know the basic tests as Steve had asked.

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