GIA Fluoro measurement

[Garry H (Cut Nut)]

Would''nt it be lovely if we could digitize diamond grading?

GIA already claim they have a colour grading device that is part of their debate settlement when graders disagree. Now there is a granted patent for Fluoro measurement.

But they still have not got an HCA patent granted

US7515251: Fluorescence measuring device for gemstones
Applicant: Gemological Institute of America, United States of America
Publication: 2009-04-07
Filed: 2007-08-24
Status: granted
A gemstone fluorescence measuring device according to the invention generally includes an ultraviolet ("UV") emission chamber, a UV radiation source, and a light meter assembly. The UV radiation source includes an upper light emitting diode ("LED") and a lower LED that radiate a gemstone under test from both above and below the gemstone. The UV radiation source provides both trans-radiation and direct radiation to the gemstone, and the UV radiation source has an adjustable intensity, thus facilitating calibration of the fluorescence measuring device. The light meter assembly includes a light detector that detects the visible light emitted from the gemstone under test in response to the UV radiation. The light detector is configured to simulate the spectral characteristics of the human eye. The fluorescence measuring device converts the measured visible light into a numerical lux reading, which can then be converted into a fluorescence grade for the gemstone under test.

 

[Modified Brilliant]

Garry, thanks for the info.

As I saw the notation "very strong blue" on a recent GIA diamond grading report,
I wondered again what defines "Very" as opposed to "strong".
Possibly a numeric grading system for fluorescence would improve understanding
the extent of fluorescence. What do you think?

www.metrojewelryappraisers.com

 

[Garry H (Cut Nut)]

Date: 5/7/2009 8:00:57 AM
Author: Modified Brilliant
Garry, thanks for the info.

As I saw the notation ''very strong blue'' on a recent GIA diamond grading report,
I wondered again what defines ''Very'' as opposed to ''strong''.
Possibly a numeric grading system for fluorescence would improve understanding
the extent of fluorescence. What do you think?

www.metrojewelryappraisers.com

Jeff it seems so dependant on the frequency or wave length of the UV and many factors.
I have seen stones that are very strong graded medium and mediums grade very strong. But what do I know?

 

[oldminer]

I will soon have a new tool to offer which I have developed on my own that will make consistent grading of UV fluorescence much less subjective without going overboard on a high-tech solution. It will be first marekted to appraisers, as I know so many of them through NAJA, and I''ll make some photos and text to describe it on Pricescope somewhere to let folks see how easy it all may be. PS: It will be well under $100 for the tool.

No, I won''t go further to describe how it works just yet. I want to get photos of the working prototype finished.