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Gemological laboratories

Name Who to ask for? Telephone Fax E-Mail URL Address
BELGIUM            
Hoge Raad voor Diamant (HRD)           Hoveniersstraat, 22 B-2018 Antwerp, Belguim
European Gemological Laboratory (EGL)           Rijfstraat, 3 2018 Antwerp, Belgium
BRAZIL            
IBGM Mrs. Jane Leao de Gama 55-11-2840233 55-11-2840545 IBGM@IBGM.com.br    
      55-61-2266720      
COLOMBIA            
Centro Gemologico Para La Investigación De La Esmeralda - (CGIE ) Mr. Rodrigo Giraldo 571-342-3986 571-3520155 emerald_research@yahoo.com    
FRANCE            
Service Public Du Control Du Diamants, Perles et Pierres Dr. Philippe Matraillet 33-14-0262545 33-14-0260675      
Laboratorie Public de Controle de Pierres Precieuses de la Chambre de Commerce           2, Place de la Bourse 75002 Paris, France
GERMANY            
German Gemmological Assoc Dr. Claudio Milisenda 49-6781-43013 49-6781-41616      
Deutsche Gemmologische Gesellaschaft EV Prof. Schloaamcher         D6580 Idar Oberstein 2 Germany
HONG KONG            
Hong Kong Gems Laboratory Mrs. Chiu Mei Ou Yang 85-28-151880 85-22-8543970      
ITALY            
Cisgem Dra. Margherita Superchi 39-2-85155250 39-2-85155258 Superchi@mi.camcom.it   Via Brisa/ Via Ansperto, 5 20123 Milano, Italy
ISRAEL            
National Gemological Institute of Israel           52 Bezalel st. Ramat Gan 52521 Israel
JAPAN            
Gemological Assoc. Of All Japan Mrs. Junko Shida 81-3-38357489 81-3-38390798      
NETHERLANDS            
Neatherlands Gemmological Laboratory Mr. Hanco Zwaan 31-71-5687596 31-71-5125337 Communications@nnm.n    
UNITED KINGDOM            
Gemmological Assoc. & Gem Testing Laboratory of Great Britain Dr. Roger Harding 44-171-4053351 44-171-8319479     27 Greville St. Saffron Hill Entrance London EC1N8SU England
UNITED STATES            
American Gemological Laboratory Mr. C.R.Beesley 1-212-7040727 1-212-7647614     580 5th Ave. S.706 New York, N.Y 10036 U.S.A
American Gemological Laboratory Mrs. Jennifer Beesley          
European Gemological Laboratory/ Gem Quality Institute            
Gemological Institute of America Mrs. Alice Keller 1-760-6034351 1-760-6034595      
SWITZERLAND            
GRL Gemresearch Laboratory            
Gubelin Gemmological Laboratory Mr. Robert Kane 41-41-4291717 41-41-4291734     Mainhofstrasse 102, CH-6000 Lucerne, Switzerland
SSEF Swiss Gemmological Institute Dr. Henri Hanni 41-61-2620640 41-61-2620641 Haennih@ubaclu.unibas.ch    
THAILAND            
Asian Institute of Gemological Science(AIGS)           Jewelry Trade Center 919/1 Silom Rd, Bangrak Bangkok 10500, Thailand




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GIA Identifies New Laser Drilling Treatment

Laser treatment to be indicated in Comments section of GIA Reports 

Researchers at the GIA Gem Trade Laboratory recently discovered a new laser drilling treatment that does not have the surface-reaching drill hole traditionally associated with laser drilling. 

In traditional laser drilling, a hole drilled to a dark inclusion in the interior of the diamond serves as a channel for the strong acid used to remove or minimize the dark material. According to Thomas Moses, Vice President of Identification Services for the Laboratory, "The most likely candidates for this new procedure are diamonds that have shallow black or dark-appearing inclusions with some type of associated tension-fracture or cleavage."

Moses described the new process as understood by GIA researchers (see figure 1): "One or more pulsed lasers are focused on the near-surface inclusion to heat it so that it expands and creates sufficient stress to extend the cleavage to the surface." This, said Moses, "provides a conduit to the dark inclusion for a treatment that most likely involves boiling (often with pressure) in strong acids to reduce the visibility of the dark inclusion. The lasering leaves evidence of one or more internal channels within the cleavage or adjacent to the inclusion, but there is no surface-reaching drill hole." 

Moses also noted a variation of the new lasering process (see figure 2) which involves "cutting a channel into the diamond with what appear to be several drill holes placed alongside each other. At first glance, this could resemble natural etching. Acid bleaching is then introduced through these channels, which have been cut to reach internal feathers or crystals." 

When a traditional laser drill hole is present, GIA policy is to note it as the first item in the Key to Symbols of the Diamond Grading Report. According to Moses, when features associated with these new lasering techniques are detected, GIA states in the "Comments" section of its Report: "Internal laser drilling is not shown." On a Grading Report, this comment, which alerts the customer to the presence of laser drilling, is in place of a symbol on the plotting diagram.

Evidence of this new treatment has been found in only a small number of stones.

Nevertheless, while research is ongoing, GIA wishes to educate members of the industry in how to detect the new laser-drilling treatment and its variation.




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