STO Contents of the gemological report

1. Introduction. Scope.

1.1. The standard of the organization "Moscow Gemological Center" (hereinafter STO MGC) is not an industry or national standard. This STO MGC defines:

1.1.1. Contents of reports of various formats issued by MGC LLC, the order of presentation and volume of information provided in standardized report forms.

1.1.2 . Tolerances for determining the parameters of examination objects reflected in reports.

1.1.3. Limitations in the use of standardized reports of MGC LLC.

1.2. This standard of the organization applies to the content of gemological reports on unmounted jewelry and jewelry-and-ornamental cut stones, as well as jewelry and jewelry-and-ornamental cut stones set in jewelry, and establishes a set of information reflected in gemological reports (conclusions and certificates) in relation to the quality characteristics of diamonds and other jewelry stones and/or inserts, their classification and terminology, tolerances and limitations, as applied to gemological reports.

1.3.  The main classification criteria of this standard correspond to the international standard ISO/TR 11211-1995 "Grading polished diamonds - Terminology and classification" (ISO/TR 11211:1995 "Grading polished diamonds - Terminology and classification") (hereinafter ISO/TR 11211:1995), the main classification criteria in the sections of competence correspond to or are comparable with those of international standards: ISO/TR 11211:1995, ISO/DIS 24016:2020 "Jewellery and precious metals - Grading polished diamonds - Terminology, classification and test methods" (ISO/DIS 24016:2020); standards of the Russian Federation: GOST R 52913-2008 "Diamonds. Classification. Technical requirements." (hereinafter GOST), STO 45866412-17-2015 "Ennobled diamonds. Classification. Technical requirements." (hereinafter STO) and TU 117-4.2099-2002 "Diamonds. Technical requirements. Classification." of the Association of Russian Diamond Manufacturers (hereinafter TU), CIBJO "The Gemstone Book"-2015, CIBJO "The Pearl Book"-2015, CIBJO "The Coral Book"-2015, Standards of organizations: "Association "Guild of Jewelers of Russia" STO 52818945-1-2016 "Jewelry inserts. Information Disclosure Rules”, “Gokhran of Russia” STO 45866412-16-2014 “Precious Stones. Terms and Definitions”, and are also comparable with those of “Gokhran of Russia” STO 45866412-15-2013 “Sapphires, Rubies Ennobled by the Diffusion Method and/or Filled with Glass (Faceted Inserts). Technical Conditions”, STO 45866412-11-2009 “Natural Processed Alexandrites. Technical Conditions”, STO 45866412-06-2008 “Natural Processed Rubies. Technical Conditions”, STO 45866412-05-2008 “Natural Processed Sapphires. Technical Conditions”, as well as with Technical Conditions TU-95.335-88 “Natural Processed Emeralds. Technical Conditions”.

2.  General Provisions.

2.1. Gemological reports on laboratory tests submitted for the study of diamonds and other gemstones and/or inserts in products or in loose form are issued on the basis of an application from an individual or legal entity as a final report on the performance of a set of works on the study of diamonds, other gemstones and/or inserts in the form of gemological reports and certificates of conformity; other forms are also possible upon agreement with the customer (such as an information letter, a detailed gemological report, etc.).

2.2.  Information on the quality characteristics of a diamond (diamonds), other gemstones and/or inserts is provided in accordance with the requirements of the international standard ISO/TR 11211-1995, as well as this standard of the organization "STO MGC", additionally (at the client's request) information on other assessment systems (GOSTs, TU, STO, etc.) can be provided for reference. For corporate clients who have their own gemological services, the assessment characteristics in the reports can be provided only according to STO MGC and/or ISO/TR 11211-1995 (for diamonds), and additional information is set out in the cover letter.

2.3.  Gemological reports provide the following information about a diamond (diamonds) and other gemstones and/or inserts in products or about loose inserts in accordance with the requirements of this standard (in accordance with the voluntary certification system of the Moscow Gemological Center), namely: its origin (if it is possible to conduct a study), the presence of treatment (if any and if it is possible to conduct a study) and its type, the weight and size of the diamond, other gemstone and/or insert, in addition, the expert report provides information on the quality characteristics of the diamond according to ISO/TR 11211-1995 and descriptive definitions of color and transparency for other gemstones and/or inserts (taking into account the setting factor that limits availability).

2.3.1. Information about a diamond (diamonds) and other jewelry stones and/or inserts in products or in loose form, in gemological reports is provided in the form of the final results of the research.

2.3.2. When issuing a gemological report on jewelry, in addition to information about the diamond (diamonds) and other inserts (if any), information is provided about the type of jewelry and its weight; in addition, the gemological report contains an indication of the value of the sample affixed to the product (without identifying the hallmark and disclosing information about the hallmark).

2.4.  Gemological certificates provide information on the conformity of a diamond (diamonds) and other gemstones and/or and/or inserts in products or on loose inserts in accordance with the requirements of this standard (in accordance with the voluntary certification system of the Moscow Gemological Center), namely: its origin (if it is possible to conduct a study), the presence of refinement (if any and if it is possible to conduct a study) and its type, the weight and size of the diamond, other gemstone and/or insert, in addition, the gemological certificate must provide information on the quality characteristics of the diamond according to ISO/TR 11211-1995 and STO MGC, as well as for other gemstones on the quality characteristics in accordance with STO MGC, including the estimated weight and/or linear dimensions (if they are available for measurement), descriptive definitions of color and transparency for other gemstones and/or inserts, as well as, at the request of the client, their compliance with the color and clarity characteristics in force in Russia regulatory and technical acts (taking into account the factor of fastening that limits accessibility).

2.4.1. Information about diamonds and other gemstones and/or inserts in products or in loose form, in gemological certificates is provided in the form of the final results of the research.

2.4.2. Work on carrying out the voluntary certification procedure and issuing a certificate is carried out on the basis of a written request from the client and the execution of an agreement on the provision of services for carrying out the voluntary certification procedure.

2.4.3. When issuing a gemological certificate for jewelry, in addition to information about the diamond (diamonds) and other inserts (if any), information is provided about the type of jewelry and its weight; in addition, the gemological report contains an indication of the value of the sample affixed to the product (without identifying the hallmark and disclosing information about the hallmark).

2.4.4. The certificate is certified by the signature of the issuing expert and the seal of the organization.

2.5. Diamonds, gemstones and jewelry for the purposes of compiling gemological reports are accepted only in a pre-prepared form, namely:

• diamonds, gemstones and jewelry must be without tags, stickers and similar attributes that change their weight or the weight of the product;
• Diamonds, gemstones and jewelry should be thoroughly washed and dried.
• It is not permitted to accept items and diamonds with contaminated surfaces for the purposes of compiling gemological reports.

3. Disclosure of information.

3.1. Disclosure of information in gemological reports (conclusions and certificates) prepared in accordance with the IGC standards implies:

• providing information on the standard name of the mineral species (in accordance with the officially registered name in the International Mineralogical Association (Russian Mineralogical Society)) and its variety (including commercial or jewelry-gemological);
• providing information about the nature of origin (natural, synthetic or artificial material);
• providing information on the quality characteristics of the jewelry insert with the mandatory indication of the technical regulations in accordance with which the graduation takes place (the names of the technical regulations are given in the note, in particular STO MGC 2016, ISO/TR 11211 and others);
• providing information on the establishment of the fact of improvement or the impossibility of establishing such a fact;
• publication of technical regulations on the IGC website, in accordance with which the assessment is carried out;

3.2. This standard of the organization is publicly available on the official website of the organization.

3.3. All issued gemological reports are available for verification online on the official website of the organization.

3.4. A full-length gemological report on laboratory tests of a diamond (or other jewelry insert) presented for study in an unmounted form contains the following information:

• Series and Number of the gemological report.
• Date of the study.
• Name of the report type.
• The name of the type of diamond or other insert material with an indication of origin in English in accordance with the IMA nomenclature and CIBJO recommendations (for example, natural - "Natural Diamond" or synthetic - "Synthetic Diamond").
• Shape and Cutting Style.
• Weight in carats.
• Linear dimensions (Measurements) in millimeters.
• Color Grade.
• Clarity Grade.
• Transparency. For colored stones and other inserts except diamonds.
• Cut Grade. For loose diamonds.
• Fluorescence assessment.
• Notes (if necessary).
• A sketch indicating the main parameters of the diamond's proportions.
• Identity diagram (if necessary, it can be issued as a separate service at the client’s request).
• Link to the official website of the organization.

3.5. A full-length gemological report on laboratory tests of a diamond (or other jewelry insert) installed in a jewelry item submitted for study contains the following information:

• Series and Number of the gemological report.
• Date of the study.
• Name of the report type.
• Name of the jewelry item (Jewelry type).
• Jewelry weight;
• Indication of sample value (if necessary);
• The name of the type of diamond or other insert material with an indication of origin in English in accordance with the IMA nomenclature and CIBJO recommendations (for example, natural - "Natural Diamond" or synthetic - "Synthetic Diamond").
• Shape and Cutting Style.
• Linear dimensions (Measurements).
• Estimated weight.
• Color Grade;
• Clarity Grade;
• Notes (if necessary);
• Photograph of a piece of jewelry;
• Link to the official website of the organization.

3.6. Detailed disclosure of information in gemological reports.

3.6.1. The combination of “Series and Number” of the gemological report is individual and belongs only to this document.

3.6.2. The date of the study indicated in the report corresponds to the actual date of preparation of the report on the results of the work performed.

3.6.3. Name of the report type:

• For full-format reports (“premium”) and reduced-format reports (“standard”) and reduced-format reports (“standard”) on diamonds, the report type is indicated – “Gemmological Certificate”, “Gemmological Report”.
• For full-format reports (“premium”) and reduced-format reports (“standard”) on jewelry stones, only the report type is indicated – “Gemmological Certificate”, “Gemmological Report”.
• For full-format reports (“premium”) and reduced-format reports (“standard”) on jewelry, only the report type is indicated – “Gemmological Certificate”, “Gemmological Report”.

3.6.4. Name of the type of jewelry (Jewelry type). For reports on inserts in jewelry. Specified in English - "Ring", "Earrings", "Pendant", "Bracelet", "Necklace", etc.

3.6.5. Weight of jewelry item. The weight value in grams is indicated, determined by direct weighing of the item with an accuracy of up to full hundredths.

3.6.6. Indication of the hallmark (Stamp). The numbers of the hallmark value are indicated; the hallmark is not decoded or the metal of the jewelry item is determined.

3.6.7. The name of the type of diamond or other insert indicating its origin: natural - "Natural Diamond" ("Natural Emerald", etc.) or synthetic - "Synthetic Diamond" ("Synthetic Emerald", etc.), if diagnostics are possible. If determining the nature of the origin is difficult, then only the name of the mineral type or variety ("Diamond", "Emerald") is indicated, and the comments indicate the fact that the origin has not been determined and the reason that does not allow for unambiguous determinations.

3.6.8. Shape and Cutting Style: The name of the cut is indicated in English in connection with the generally accepted international names, or the official patented name of the cut.

3.6.9. Weight in carats: The weight in carats for loose stones is determined by direct weighing, in products the weight of inserts is calculated in accordance with the measurements taken using empirical formulas for specific types of cutting with the introduction of appropriate corrections for proportions, and if it is impossible to carry out all the necessary measurements, a standard calculated weight is determined based on the available linear parameters, assuming the ideal proportions of the insert. In reports on a jewelry item, the calculated weight may not be indicated for inserts of artificial origin, rocks or granular aggregates of minerals, as well as for amber and pearls.

3.6.10. Linear dimensions (Measurements) in millimetres (up to and including full hundredths). Provided for diamonds and other jewellery inserts when issuing gemological reports on single loose stones measuring 2 mm and larger. When issuing gemological reports on jewellery, linear dimensions are specified only if it is possible to measure inserts by length-width (diameter) and height. The dimensions of a single central diamond insert are specified starting from 3 mm in width of the insert, and of another jewellery stone starting from 5 mm in width of the stone. The dimensions of the central diamond with side stones are specified starting from 0.30 carats. The dimensions of the central insert made of a precious stone with side stones are specified starting from 0.50 carats. The sizes of central inserts of non-precious stones, set in a circle of side inserts, are indicated starting from 3.00 carats. Linear dimensions are also indicated for pearls, amber, for inserts of artificial origin, rocks or granular aggregates and minerals.

3.6.11.  Color Grade. For diamonds, color characteristics are specified regardless of the size of the inserts. For gemstones classified as precious in accordance with Russian legislation, the color shade (descriptive characteristic) is specified, and, at the client's request, for stones of 0.5 carats or more, provided that a premium gemological report is issued, a detailed description of the color is provided in accordance with the GIA gemset. Conformity of the color characteristics to industry regulations in force in Russia is mandatory in all gemological reports of the certificate type in a footnote to the description. For other natural gemstones, the color shade (descriptive characteristic) is specified, and for stones of 3.00 carats or more, provided that a premium gemological report is issued, a detailed description of the color is provided in accordance with the GIA gemset, at the client's request. For pearls and amber, the color shade is indicated (descriptive characteristic). For artificial and synthetic inserts, a general verbal description of the color shade is given.

3.6.12.  Clarity Grade. For diamonds, clarity grades are specified regardless of the size of the inserts. For gemstones classified as precious in accordance with Russian legislation, clarity grades (in accordance with the IGC classification) are specified for stones of 0.5 carats and over, provided that a premium gemological report is issued. Conformity of clarity grades to industry regulations in force in Russia is required to be included in all certificate-type gemological reports in a footnote to the description. For other natural gemstones, clarity grades are specified for stones of 3.00 carats and over, provided that a premium gemological report is issued. Clarity grades are not specified for pearls and amber. Clarity grades are not specified for artificial and synthetic inserts.  

3.6.13.  Transparency. Specified for precious and other jewelry stones and inserts, except for diamonds, pearls and mother-of-pearl.

3.6.14. Cut Grade. This option is provided in reports for loose diamonds. Polish and Symmetry grades are also provided as additional grades. For diamond shapes other than round, the proportion grade is not provided, but the symmetry and polish grades are provided.

3.6.15.  Fluorescence assessment. Specified for loose diamonds, for single diamonds in items over 0.3 carats in size, and for central inserts in items highlighted in the report by a separate description for each insert. For other gemstones, fluorescence assessment may not be specified if it is not a diagnostic or evaluation feature.

3.6.16.  Notes and comments (if necessary). Notes and comments shall specify the conditions and limitations concerning the examination results, the identified signs of enhancement, both for natural and synthetic stones. In gemological reports, if it is impossible to conduct research to establish the fact of enhancement of a natural or synthetic diamond or other gemstone, the notes, or footnote, shall necessarily indicate that “the fact of enhancement was not established” (provided that the insert is highlighted in the report by a separate description), or for a group of inserts – the limiting condition “Determination of the material, nature of origin, enhancement of inserts and their quality characteristics was carried out without unmounting from the setting”. If it is possible to determine the fact of enhancement of the stone in the product without unmounting from the setting, or to conduct research of the insert in the unmounted form, then the notes shall necessarily indicate the fact of the presence of enhancement signs or their absence.

3.6.17. Sketch indicating the main parameters of the diamond cut proportions (for gemological reports on loose diamonds and synthetic cut diamonds). An idealized cut diagram is provided in plan from the crown and pavilion side, as well as a diagram in profile indicating the main linear parameters of the cut proportions in percentages and in degrees – the main angular parameters.

3.6.18. Identity diagram (for gemological reports on loose diamonds and synthetic cut diamonds, it is issued as a separate service at the client’s request). The identity diagram reflects the main external and internal defects of the diamond, allowing its identification.

2.2.6.19. Link to the official website of the organization. In the lower right corner, the address of the site is indicated, where you can check the compliance of the reports, as well as familiarize yourself with the standards of the organization.

4. Tolerances

4.1. When determining the mass of a loose diamond or other gemstone, its weight is determined to one thousandth of a carat with an error of ±0.001 ct. In conclusion, the weight is given in full hundredths of a carat. An exception is the rounding rule for the third nine after the decimal point. Thus, the weight of a 0.998 carat diamond will be indicated as 0.99 ct., and the weight of a 0.999 carat diamond will be reflected as 1.00 ct.

4.2. When calculating the mass of a standard-cut diamond installed in a product, depending on the degree of restriction on viewing the diamond's cut elements, an error of up to 5% is allowed.

4.3. When calculating the mass of a diamond installed in a product that has a shape and cut type different from the standard cut, depending on the degree of restriction on viewing the diamond's cut elements, an error of up to 10% is allowed.

4.4. When calculating the mass of a standard-cut gemstone installed in a product, depending on the degree of restriction on viewing the diamond's cut elements, an error of up to 10% is allowed.

4.5. When calculating the mass of a gemstone installed in a product that has a shape and cut type different from the standard cut, depending on the degree of restriction on viewing the cut elements, an error of up to 20% is allowed.

4.6. When determining the linear dimensions of a diamond or other stone in a jewelry item (if access is restricted), the linear dimensions of diamonds may be given in whole tenths of a millimeter. Depending on the type of fastening, an error in measuring the linear dimensions of a diamond in a jewelry item of up to 5% is allowed.

4.7. When determining the linear dimensions of a diamond or other stone in a piece of jewelry, in the absence of the possibility of directly measuring the linear dimensions, the determination of such for calculation is made on the basis of the standard proportions of a diamond of the corresponding type of cut, taking into account the deviations manifested in the geometry and optical effects of the cut.

4.8. When determining the mass of a piece of jewellery for the purposes of compiling a gemological report, its weight is determined to one thousandth of a gram with an error of ±0.001 g. The conclusion provides the weight of the jewellery in full hundredths of a gram.

4.9. When determining the quality characteristics of diamonds installed in a piece of jewelry, a deviation from those in an unmounted form of up to 1-2 gradations is allowed, depending on the type and nature of the setting.

4.10. When determining the quality characteristics of diamonds with a diameter of less than 3.0 mm, installed in a jewelry item, the presence of diamonds of adjacent quality groups in an amount of up to 5% is allowed, depending on the nature of the setting.

5. Limitations

5.1. The standard of the organization "Moscow Gemological Center" (hereinafter STO MGC) is not an industry document or a national standard.

5.2. All gemological reports (conclusions, certificates) are provided exclusively at the voluntary request of the client (individual or legal entity).

5.3. All characteristics determined in accordance with the STO MGC and indicated in gemological reports (conclusions, certificates) should be considered only in connection with international, national and industry standards.

5.4. MGC (Moscow Gemological Center) LLC shall not bear any liability (legal, economic or any other types of liability) for lost profits, reputational losses or other damage that may be caused in connection with the use of the MGC gemological report.

5.5. Each gemological report (conclusion, certificate) is provided exclusively for a specific diamond (or cut diamond) or jewelry item. LLC MGC (Moscow Gemological Center) does not bear responsibility (legal, economic or any other types of responsibility) for the subsequent full or partial substitution of the subject of the examination after the issuance of the gemological report.

5.6. Each gemological report (conclusion, certificate) is current at the time of issue, determined by the technical, methodological and legislative conditions for conducting research and testing, as well as registration and issuance.

5.7. Each gemological report is a complete document containing a set of interrelated information that is not subject to alienation. LLC MGC (Moscow Gemological Center) is not responsible for any changes made to the (conclusion, certificate) after the moment of issue.

5.8. LLC MGC (Moscow Gemological Center) does not bear responsibility (legal, economic or any other types of responsibility) for the unlawful use of the conclusions and certificates of MGC in relation to third parties.

5.9. "MGC" is an officially registered trademark protected in accordance with the copyright of the copyright holder in the territory of the Russian Federation. Reproduction of this gemological report (conclusion or certificate), or any part of it (except for the original issued to a specific client), without the written consent of MGC is prohibited.