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 Post subject: Presidium Gem Tester - Colored Gem Stones & Simulants
PostPosted: Sun Nov 09, 2014 2:20 am 
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Hi,

I came across a Instrument name "Presidium Gem Tester" Can it be use to recognize lab created Gemstones and syntactic Gemstones ? Is it accurate ?

Thank you,


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 Post subject: Re: Presidium Gem Tester - Colored Gem Stones & Simulants
PostPosted: Sun Nov 09, 2014 2:11 pm 
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Presidium is a good name. Check at the bottom of the product page for the documentation downloads, they should fill you in on all you need to know. I think the fact that they call it an "estimator" is a good indication that it's not going to be the only tool you need in your box, but it's up to you if it suits your needs.

http://www.presidium.com.sg/PGT.html


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 Post subject: Re: Presidium Gem Tester - Colored Gem Stones & Simulants
PostPosted: Sun Nov 09, 2014 2:28 pm 
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hafiz wrote:
Hi,

I came across a Instrument name "Presidium Gem Tester" Can it be use to recognize lab created Gemstones and syntactic Gemstones ? Is it accurate ?

Thank you,

No.


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 Post subject: Re: Presidium Gem Tester - Colored Gem Stones & Simulants
PostPosted: Mon Nov 10, 2014 12:04 am 
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Barbra Voltaire wrote:
hafiz wrote:
Hi,

I came across a Instrument name "Presidium Gem Tester" Can it be use to recognize lab created Gemstones and syntactic Gemstones ? Is it accurate ?

Thank you,

No.


Hi,

Barbra thank you for your reply. is a refractometer a good tool to test synthetic and lab created gemstones ? or is there any other tools to check ?


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 Post subject: Re: Presidium Gem Tester - Colored Gem Stones & Simulants
PostPosted: Mon Nov 10, 2014 11:29 am 
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hafiz wrote:
is a refractometer a good tool to test synthetic and lab created gemstones ? or is there any other tools to check ?


no, the refractometer identify the material, not if it's natural or man made. My 1st advice for you is to learn gemology AND the use of the instruments involved in gem ID, there is NO such an instrument that identify the stone without requiring a certain level of gemological knowledge from the operator..... :wink:

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 Post subject: Re: Presidium Gem Tester - Colored Gem Stones & Simulants
PostPosted: Mon Nov 10, 2014 12:21 pm 
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Alberto's advice is spot on.
Different gems will have different methods of synthesis and treatment. Therefore one must understand how to identify a specific gem and then, research whether or not that specific gem can be synthesized and treated and how to recognize that with standard gemological instrumentation.

It involves, not only understanding gemology, but thorough understanding of how to interpret the results of the instrumentation you are using and the limits of that instrumentation.


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 Post subject: Re: Presidium Gem Tester - Colored Gem Stones & Simulants
PostPosted: Tue Nov 11, 2014 4:59 am 
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Thank you All for your advise. i think the best way for know is the get a gemologist to certify Gemstone before purchase.


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 Post subject: Re: Presidium Gem Tester - Colored Gem Stones & Simulants
PostPosted: Tue Nov 11, 2014 11:15 am 
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hafiz wrote:
i think the best way for know is the get a gemologist to certify Gemstone before purchase.


i think you nailed it! although gemologists usuallly do not "certify" anything, they usually release reports about gems.... ;-)

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 Post subject: Re: Presidium Gem Tester - Colored Gem Stones & Simulants
PostPosted: Fri Nov 21, 2014 12:25 pm 
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hafiz wrote:
Hi,

I came across a Instrument name "Presidium Gem Tester" Can it be use to recognize lab created Gemstones and syntactic Gemstones ? Is it accurate ?

Thank you,


I use it, it's very easy to get max RI value,
but i have cheap china traditonal refractometer really2 hard to read the index...

Regards

Joel


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 Post subject: Re: Presidium Gem Tester - Colored Gem Stones & Simulants
PostPosted: Sat Nov 22, 2014 12:02 am 
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No, Joel, you can't get a refractive index because The Presidium is a reflectometer not a refractometer.

Have you considered reading through the Gemology Project?
http://www.gemologyproject.com/wiki/ind ... f_Contents
and perhaps
The Introduction to Gemology:
http://www.bwsmigel.info/


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 Post subject: Re: Presidium Gem Tester - Colored Gem Stones & Simulants
PostPosted: Sat Nov 22, 2014 12:28 am 
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Owh, sorry, hehehe..
I am sleepy...

I have refractometer like this:
http://www.ebay.com/itm/Gemology-Gemsto ... 0732800516

It's very hard to get the value, don't know if i buy Gia standard.

and i have also refractive presidium like this:
http://www.ebay.com/itm/PRIM-II-Presidi ... 1223857004
-------------------------

Sorry, this is topic about presidium PGT:
http://www.ebay.com/itm/Presidium-Gem-T ... 1585588249

Yes i also using Presidium PGT.
It's very easy and simple to use it...
I compare with gemlogis pistachio ciel vs presidium pgt, they both is good, i test on ruby and sapphire with this tools, all result is same...
But sure both tester cannot to check sintetic...
But PGT cannot check moissanite...

Presidium have special tools to check sintetic or not, but only for Ruby...and only very small ruby...
Gemlogis have special tools to check sintetic diamond or natural.

Regards

Joel


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 Post subject: Re: Presidium Gem Tester - Colored Gem Stones & Simulants
PostPosted: Sat Nov 22, 2014 1:40 am 
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My post stands, that Presidium in not a refractometer, it is a reflectometer.
Have you thought of reading through the GemologyProject?


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 Post subject: Re: Presidium Gem Tester - Colored Gem Stones & Simulants
PostPosted: Sat Nov 22, 2014 3:33 am 
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Thanks barbra...iam sorry if this tools is diff tools...
What is correct tool to get RI value?

I have refractometer like this:
http://www.ebay.com/itm/Gemology-Gemsto ... 0732800516

and i have Presidium Refractive Index Meter II (PRIM II).
http://www.presidium.com.sg/PRIM2.html

I don't have Presidium Reflectivity Meter (PRM).
http://www.presidium.com.sg/PRM.html
----------------
As i read RI value list:
Diamond 2.417.
Sapphire / Ruby 1.757 - 1.779.

So i compare with my tool name is: Presidium Refractive Index Meter II (PRIM II).
http://www.presidium.com.sg/PRIM2.html
All the RI value is same like in the general list of Ruby/Sapphire/Diamond and easily to get the index value, not like traditional refractometer like i have before...

Please see the picture below, i connect the PRIMII with PC, with sapphire on PRIMII, RI Value 1.775.

Image

Regards

Joel

Sorry all for OOT.


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 Post subject: Re: Presidium Gem Tester - Colored Gem Stones & Simulants
PostPosted: Sat Nov 22, 2014 5:51 am 
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Joel,

what is labeled by Presidium as "refractive index meter" is NOT a refractometer, it's indeed a reflectometer. Please follow Barbra's advice and have a DEEP read to the suggested pages in the gemology project............

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 Post subject: Re: Presidium Gem Tester - Colored Gem Stones & Simulants
PostPosted: Sat Nov 22, 2014 6:54 am 
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Yeah thanks alberto, i don't know if PRIM2 ALSO is not correct call "Refractometer", and bettween Refractometer is DIFFERENT with "REFRACTIVE" index meter.

Because Presidium give name PRIM as "Reflective".
http://www.presidium.com.sg/PRM.html

And Presidium give name for PRIMII as "Refractive" Index Meter II.

Also on the IGEM.COM, PRIMII IGEM say name is REFRACTOMETER? hehehe, make me more confused...
http://www.igem.com/Presidium-Refractiv ... meter.html

So sorry, to bother you....

I have read on http://www.gemologyproject.com/wiki/ind ... ractometer
and i already have the cheap one, made-in china, but really hard to read the index.
----------------------------
IF i buy GIA standard refractometer:
http://www.ebay.com/itm/GIA-GEM-INSTRUM ... 1458964933
Around 800usd.
This refractometer for reading RI VALUE?

Regards

Joel


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