WELCOME

Welcome to the Gemological Science Education and Gem Testing Laboratory at
Gemological Hallmark International Co.,LTD.

Gem Testing Laboratory
“GHI” is a Gem Testing Laboratory society based only in Thailand.

To be one of the most honest diamond and colorstone laboratory in the world to conform to the rules for grading polished gem-diamonds set by the international buyers or traders.

Aims to serve as the principal honesty to develop, promote and support the Thai gem and jewelry industry to be able to compete in the global market."

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GEM & JEWELRY TESTING LABORATORY

This identification covers the conclusions of “GHI” laboratory reports expert who have carefully graded, tested, examined and analyzed the stone by means of specialized instruments available at the Laboratory at a time of examination. They have drawn up the report according to the highest professional standards.

All report will be printed on original package. No corrections or alternations of any form shall be accepted on the gemstone report, and all gemstone report are laminated for protection.

Gem Identification Report:

This report contains the identification of loose gemstone by description, measurement, color, weight, cut and stating an opinion on their authenticity, and treatment(s).It does not constitute a guarantee for or an appraisal of the object or gemstone described therein.

Color-Stone G Report pricelist

Gem & Jewelry Identification Report:

This report contains the identification of loose gemstones or diamond by photographic images, description, measurement, color, weight and stating an opinion on their authenticity and treatment(s).It does not constitute a guarantee for or an appraisal of the object or gemstone described therein.

Color-Stone J Report pricelist

Diamond J Report pricelist

Gem & Jewelry Identification Clarity Report:

For gem or diamond; by photographic images, description, measurement, weight, clarity grade, color grade, proportion, finish grade and fluorescent and stating an opinion on their authenticity, and treatment(s).It does not constitute a guarantee for or an appraisal of the object or gemstone described therein.

Color-Stone C Report pricelist

Diamond C Report pricelist

Gem & Jewelry Identification Full Report:

This report contains the identification of gemstones set in jewelry or loose, this report contains photographic images, description, measurement, color, weight, clarity grade, proportion, finish grade, refractive index, specific gravity and stating an opinion on their authenticity, variety and trade name and treatment(s).

It does not constitute a guarantee for or an appraisal of the object or gemstone described therein. The physical appearance of a jewelry or gemstone may differ from its photographic image in the report.

All Report will be printed on original paper and will bear an official signature of gemologist, No corrections or alternations of any form shall be accepted on the pack report, and will laminated for protection.

Color-Stone Full Report Pricelist

Diamond Full Report Pricelist

Standard Gemological Identification Report Wording;

Updated: January 2010

Comment(s) for Natural Sapphire 'Padparadscha.'

Sapphire is a variety of corundum the color is a subtle mixture of pinkish orange to orangey pink with pastel tones and low to medium saturations.

The Natural Sapphire (padparadscha) or 'padparadscha sapphire' can be applied to both unheated and heated; But shall not be applied in the following cases:

(1) If the stone has any color modifier other than pink or orange.
(2)If the stone has uneven color, distribution when viewed with unaided eye, table up +/- 30?.
(3)If the stone treated with foreign light element or/an external source.
(4) If the stone has been treated by irradiation, dyed, coated, or painted

Comment(s) for Natural Ruby and Sapphire 'Unheated'

Any corundum (Natural Ruby and Sapphire) that shows no indications of having undergone heat treatment shall be described as,

NOTE: The comment shall be described as; No heat enhancement process was applied. (Unheated)

Note: In some certain heating conditions may not modify some internal characteristics, other features, if spectral data indicate heating has taken place, The comment shall be described as; (Heated)

Comment(s) for Natural Ruby and Sapphire 'Heated'

Any corundum (Natural Ruby or Natural Sapphire) that shows indications of having undergone heat treatment or e.g., Method;

          Method: heating followed by controlled cooling (heated above 1600 C and then slowly cooled) and also heating and slow cooling {to improves or creates                         asterism (star)}

          Method: heating is common use for removes purple or brownish color component; Also hides cracks and improves color

          Note: In some certain heating conditions may not modify some internal characteristics, other features, if spectral data indicate heating has taken place, the comment shall be described as; (Heated)

NOTE: The comment shall be described as;

          Heat enhancement process was applied. (Heated)

Comment(s) for Natural Ruby and Sapphire ' beryllium treatment '

Any corundum (Natural Ruby or Natural Sapphire) that shows indications of having undergone heating (is commonly use in the trade) in natural beryllium in corundum treatment; beryllium is found mostly in the mineral beryl{ALBE 2 (Si 8 O18)}; chrysoberyl [Al 2 BeO4], phenakite [Be2SiO4], bromellite [BeO], and others.

NOTE: The comment shall be described as; Heat enhancement with light elements was applied. Treatment is permanent
          Or
          Further analysis on whether foreign element has been introduced is required.

Comment(s) for Natural Ruby and Sapphire ' lead glass '

Any corundum (Natural Ruby or Sapphire) that shows indications of having undergone heating with residue from the heating process present in healed fissures and/or cavities; shall be describe as a degree to which fissure “healing” has occurred, and the residue that remains within the healed fissures and cavities, this also shows indications of heat treatment and a degree of healing along which also contain residue from the heating process, (to modify the color or transparency of the stone and also adds weight); Flux (synthetic) assisted healing of a fracture during the heating process, or other materials during the heat treatment or crystal growth processes, indications of having undergone heat treatment and the presence of a vitreous residue in a cavity(ies), It is possible that during the clarity enhancement process in addition to fractures, cavities may become filled with the clarity enhancing substance being used, i.e., glass.

NOTE: The comment shall be described as; Heat enhancement with minor foreign substance (lead glass) filled in cavities.
          Or
          Heat enhancement with foreign substance (lead glass) filled in cavities.

The presence of materials within fractures that have occurred naturally are not within the context of this clause and need not to be declared.

Comment for Natural Ruby and Sapphire ' diffusion '

Any corundum (Natural Ruby or Sapphire) that shows indications of having undergone heating accompanied by the introduction/diffusion of a chemical element(s) (Heating in the presence of titanium oxide or other coloring agents) To improves or creates asterism, or diffuses color onto the surface of the stone, from an external source Or “surface diffusion”. (avoid recutting)

NOTE: The comment shall be described as; Evidence of diffusion of a chemical element(s) from an external source.

ADDRESS:
Gemological Hallmark International Co.,LTD
The Silom Galleria 3rd Floor Room 312
919/1 Silom Road Bangrak Bangkok 10500 Thailand

Tel: (662) 2362131

E-mail: info@ghi.co.th