National Shutdowns have put the lid on most shows.
Welcome to the GemologyOnline.com Forum
A non-profit Forum for the exchange of gemological ideas
It is currently Fri Aug 07, 2020 2:01 pm

All times are UTC - 4 hours




Post new topic Reply to topic  [ 12 posts ] 
Author Message
 Post subject: Gem N Eye III digital refractometer
PostPosted: Tue Jul 16, 2013 11:45 am 
Offline
New to the Forum or The Quiet Type

Joined: Tue Jul 16, 2013 11:15 am
Posts: 3
I made the mistake of purchasing one of these pieces of junk from mineralab.com.
I spoke with the owner, Tim Flanegin, extensively about how well they worked and was assured that it worked well. IT DOESN'T AT ALL
I have tried it on around 100 stones and it has given me a reliable reading maybe 5% of the time. And those were only on OTL stones or glass. Immediately after receiving it I complained and was told that it was something I was doing wrong: the stone was dirty, etc. Tim even tried to say that I wasn't using real sapphires once. I wanted it to work out, so he allowed me to trade units. The second one worked the same. I have asked to return it and have even agreed to pay a restocking fee, but he has stopped returning my emails.

AVOID THIS "REFRACTOMETER"


Top
 Profile  
Reply with quote  
 Post subject: Re: Gem N Eye III digital refractometer
PostPosted: Tue Jul 16, 2013 1:23 pm 
Offline
Site Admin
User avatar

Joined: Sun Oct 16, 2005 12:22 pm
Posts: 20284
Location: San Francisco
It has been my experience with the reflectometer, (they are not technically refractometers) that they need to be calibrated often.

Using known gems....quartz, synthetic corundum, synthetic flame fusion spinel, one can calibrate these units pretty successfully.
Then they will work for the next unknown you test.

Next time you use it, test it with your known gems again. Recalibrate and then recalibrate again.


Top
 Profile  
Reply with quote  
 Post subject: Re: Gem N Eye III digital refractometer
PostPosted: Tue Jul 16, 2013 3:08 pm 
Offline
Platinum Member
User avatar

Joined: Tue Jan 02, 2007 8:20 pm
Posts: 2657
I think the Gem N Eye attempts to be "all digital" and is not able to be manually calibrated, as have most previous analog reflectometers.

I have not played with one of these but was immediately suspicious of the unit because it has a digital look up table to suggest the ID of the gemstone. I would run in the other direction from ANY reflectometer that purports to measure birefringence or has a built in look up table. (there is another similar one from Austria that one of our list members a HIGHLY experienced gemologist, had an essentially identical experience with. Bought the unit with high hopes. Lots of BS interactions with the developer. Asked for a refund. Developer goes off the air. )

I would suggest initiating a charge back with your credit card.

Dr. Bill Hannemann's latest model has you check against known stones each time. He has done away with the screwdriver cal adjustment and replaced it with an adjustment knob.

Similarly the Presidium model comes optionally with a set of four or five OTL stones to adjust the calibration against.

Reflectometry is a very twitchy measurement for Gem ID. Dr. Hannemann who has sold as many of these as anyone refers to it as a confirmative rather than determinative measurement. It is really a very weak piece of data and I would never depend on it being accurate. For one thing the measurement of "reflected" light has no way to distinguish between light reflected at the surface of the gemstone (what you are trying to measure) and light that has entered the gemstone and been "retroreflected" by the pavilion. You can try to minimise this by sliding the gem over the measurement port but it is difficult to determine what you are really getting.

Thank you for posting this warning for everyone. I suspected that was the case with that instrument but had not had the opportunity to try it out.


Top
 Profile  
Reply with quote  
 Post subject: Re: Gem N Eye III digital refractometer
PostPosted: Tue Jul 16, 2013 3:16 pm 
Offline
Site Admin
User avatar

Joined: Sun Oct 16, 2005 12:22 pm
Posts: 20284
Location: San Francisco
Thanks Gene, I don't have this particular model.....but the one I do have is a royal bother.


Top
 Profile  
Reply with quote  
 Post subject: Re: Gem N Eye III digital refractometer
PostPosted: Tue Jul 16, 2013 3:20 pm 
Offline
Gemology Online Royal Princess

Joined: Mon Oct 17, 2005 10:56 am
Posts: 6462
Location: The frozen north prairie :-/
I have an old Jemeter 80 I'd be willing to sell to any masochists lurking on the forum 8) .

_________________
IIJA Registered Gemologist
GIA Graduate Gemologist


Top
 Profile  
Reply with quote  
 Post subject: Re: Gem N Eye III digital refractometer
PostPosted: Tue Jul 16, 2013 3:33 pm 
Offline
Valued Contributor

Joined: Fri May 26, 2006 2:35 pm
Posts: 143
Location: belgium
Hi,

I made the mistake, a few years ago, to buy a gemmeter from a guy living in Germany. The thing is manufactured in Austria. Paid more or less 750 U$.
Worst piece of crap I ever bought.
You switch the thing on, have to wait a few minutes, then you start calibrating and after 15/20 minutes it is calibrated. Then you can measure a stone or two, and if you switch the thing off, you can start all the procedure again, really getting on my nerves! :evil: :evil: :evil:


Top
 Profile  
Reply with quote  
 Post subject: Re: Gem N Eye III digital refractometer
PostPosted: Tue Jul 16, 2013 3:38 pm 
Offline
Site Admin
User avatar

Joined: Sun Oct 16, 2005 12:22 pm
Posts: 20284
Location: San Francisco
:idea: Yes...that's the one I have as well.


Top
 Profile  
Reply with quote  
 Post subject: Re: Gem N Eye III digital refractometer
PostPosted: Tue Jul 16, 2013 3:39 pm 
Offline
Valued Contributor

Joined: Fri May 26, 2006 2:35 pm
Posts: 143
Location: belgium
I agree that there are more pleasant ways to throw money away :lol:


Top
 Profile  
Reply with quote  
 Post subject: Re: Gem N Eye III digital refractometer
PostPosted: Tue Jul 16, 2013 7:51 pm 
Offline
New to the Forum or The Quiet Type

Joined: Tue Jul 16, 2013 11:15 am
Posts: 3
I spent a lot of time calibrating the machine. It has multiple ranges that can be calibrated based on a certain stone. So, say you calibrate Quartz, it adjusts any stone with an RI in the Quartz range by whatever the amount your calibration was. It didn't matter if i calibrated the machine up or down as the machine was way off and not in one direction or another. it just plain doesn't work. And the owner kept telling me that it was my fault because the stone or lens was dirty, but I followed the directions to a "T" because I wanted something easier than a critical angle refractometer


Top
 Profile  
Reply with quote  
 Post subject: Re: Gem N Eye III digital refractometer
PostPosted: Wed Jul 17, 2013 3:31 pm 
Offline
Platinum Member
User avatar

Joined: Tue Jan 02, 2007 8:20 pm
Posts: 2657
Definitely not your fault. Your experience is 100% consistent with everybody elses.
Thank you for taking the time to blow the whistle on yet another piece of junque.


Top
 Profile  
Reply with quote  
 Post subject: Re: Gem N Eye III digital refractometer
PostPosted: Sat Jul 20, 2013 6:13 pm 
Offline
Valued Contributor
User avatar

Joined: Sun Jul 15, 2012 6:29 pm
Posts: 321
Location: Los Angeles, CA
G4Lab wrote:
Dr. Hannemann who has sold as many of these as anyone refers to it as a confirmative rather than determinative measurement. It is really a very weak piece of data and I would never depend on it being accurate.


Amen.

_________________
The Art of Photomicrography:
http://www.dannyjsanchez.com
http://mineralien.tumblr.com


Top
 Profile  
Reply with quote  
 Post subject: Re: Gem N Eye III digital refractometer
PostPosted: Thu Jul 09, 2020 8:09 pm 
Offline
New to the Forum or The Quiet Type

Joined: Thu Jul 09, 2020 9:13 am
Posts: 1
I have one and have had it for over 2 years. It is very accurate I've verified and identified (which takes many inputs/different tests to do) with the gem n eye 3.

The more jeweler grade your stone is the easier the machine tests. Tim gives you two test stones, then you can calibrate the machine manually based off known or certified gem quality stones.

It takes patience but if you are receiving stones from overseas their typically not fake but many of them are misidentified. If your machine is reading the same thing over and over you must consider a good possibility it was not accurate in someone's assumption. To identify you will need atleast the conductivity tester, a number one helps for the inputs. I've verified and identified over 50 stones types using this computer with other assisting tests as input into the machine.

For less than optimal stone polishing them must be heavy. Their not all going to test perfectly because they maybe on cusp of other stone identification properties. This is where get a good median(slightly higher or lower) can come into play. Vigilants and patience.


I have for identification hardness test, conductivity, specific gravity scale, calcite pleoclorism scope. A pleoclorism chart comes in handy. These are all the major inputs for the gem-n-eye 3.

Many stones are confused because their conductivity is in the range of glass or another stone.


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 12 posts ] 

All times are UTC - 4 hours


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group
Gemology Style ported to phpBB3 by Christian Bullock