Refractometers - Need help

[maxspinel]

I''ve trying to get a refractometer. I did some research and there are the GIA Gem Instruments Duplex II, Rayner Dialdex or London and of course, some no brand products.

The Duplex seems quite expensive. Does anybody have some recommendations on what is the difference between these products and is the Duplex worth the extra money? Also, do we need a light source to go with the refractometer or the polariscope?

Thanks

 

[Barbara]

Hi Max,

I can''t speak to the difference between brands as I''ve always used the Duplex, but I can tell you that the GIA polariscope has its own light source, which also functions as the needed light source for the refractomer.

Barbara

 

[maxspinel]

Date: 10/16/2006 3:58:29 PM
Author: Barbara
Hi Max,

I can''t speak to the difference between brands as I''ve always used the Duplex, but I can tell you that the GIA polariscope has its own light source, which also functions as the needed light source for the refractomer.

Barbara

Barbara,
Thanks for the reply. I know the GIA polariscope is illuminated but how do you use that as a light source for the Duplex? Since I am going to take the GIA gem identification class, I need to purchase some equipment. I am thinking either to buy the entire GIA Colored GEM ID package which is fairly expensive or buy individual component separately. It seems that the polariscope construction involves only polarized lens; therefore, some non name brand products can do just fine with a flash light as illuminated source. However, refractometer is critical and from my reading that the GIA Duplex has an edge in spot reading the cabochons while Rayner is another leading brand used in Europe. Some said the Rayner Dialdex is more accurate than the Duplex. Any other input will be greatly appreciated.

 

[DiamondExpert]

Kassoy.com - http://www.kassoy.com/gemology/gemology04.html

 

[Barbara]

Date: 10/17/2006 3:33:46 PM
Author: maxspinel

Date: 10/16/2006 3:58:29 PM

Thanks for the reply. I know the GIA polariscope is illuminated but how do you use that as a light source for the Duplex? Since I am going to take the GIA gem identification class, I need to purchase some equipment. I am thinking either to buy the entire GIA Colored GEM ID package which is fairly expensive or buy individual component separately. It seems that the polariscope construction involves only polarized lens; therefore, some non name brand products can do just fine with a flash light as illuminated source. However, refractometer is critical and from my reading that the GIA Duplex has an edge in spot reading the cabochons while Rayner is another leading brand used in Europe. Some said the Rayner Dialdex is more accurate than the Duplex. Any other input will be greatly appreciated.

Hi Max, you simply set the polariscope behind the refractomer and turn it on. The polariscope has a light port in front that matches up perfectly with the one in back of the refractometer.

Barb

 

[maxspinel]

Date: 10/18/2006 12:06:01 PM
Author: Barbara

Date: 10/17/2006 3:33:46 PM
Author: maxspinel


Hi Max, you simply set the polariscope behind the refractomer and turn it on. The polariscope has a light port in front that matches up perfectly with the one in back of the refractometer.

Barb

Thanks Barbara. If I order only the GIA refractomer w/o their polariscope, do I need to buy a separate light source for the Duplexr?

Max

 

[C Smith]

You will need some sort of light source. Monochromatic light is preferred in many cases. I just use the polariscope''s light aperture.