Terms and Conditions


• These Terms and Conditions for gem identification and grading activities (hereinafter the “Terms and Conditions”) stipulate the rights and obligations between GUILD Gem Laboratories (hereinafter GUILD) and a client requesting identification and grading of gemstones.


• GUILD provides identification and grading on species and variety, treatment, origin of gemstones, in forms of identification certificate, gemmology report, grading report and verbal opinion (hereinafter, the Services). GUILD will only provide testing requested by the client.


• Neither the client nor any purchaser of the article (s) shall deem such gem certificate, gemology report and verbal opinion as a guarantee, valuation or appraisal for tested items, and GUILD has no representation or warranty regarding the Services described herein.


In the event of any claim by the client or any person for damage to the tested items, or damages resulting directly or indirectly from the Services, the liabilities of GUILD shall in no event exceed 2 times the amount it receives from the client.


This report contains a record of the physical data of the tested items, including nature of the stone, identity, treatments and alterations made to the stone, as applicable.


All GUILD reports and certificates are printed on original paper and bear official signature. No correction or alteration of any form shall be accepted on the reports or certificates. A GUILD report or certificate contains the identification of gemstones by photographic image (s), descriptions, measurements and weight, tested data and states an opinion on their identity, treatment, quality and rarity, when applicable.


This report or certificate contains only the characteristics and conditions of the article described herein after grading, testing, examination and analysis by using the techniques and equipment available to GUILD at the time of examination. Determination of identity and other data is based on the chemical and physical properties and internal characteristics, using magnification, standardized viewing environment and light source, standard and (or) advanced gemological instruments as deemed necessary.


All gem identification and testing are conducted by experienced GUILD gemologists on independent basis. Opinions may vary in terms of characteristics covered in this report, and results of the examination may differ upon (i) when, how and by whom the article is examined (ii) changes and improvements in technology and equipment that enable the lab to detect, among other things, treatments previously undetectable, or alterations which becomes reversible, even if the process remains undetectable.


Neither GUILD nor any of its staff shall, at any time, be held responsible for any discrepancy which may result from the application of new technology or methods.


The client acknowledges and agrees:


• Not all origins of gemstones are detectable;

• Gemstone can be treated, retreated, altered or otherwise processed after identified or tested by GUILD;


• Advancement of technology may cause or result in a tested item being undetectable of its treatment and (or) synthetic nature at the time of testing when no recognised testing method is publicly available.


The client agrees not to hold GUILD and its employees liable for any loss or damage, special, incidental, or consequential loss, etc. arising from, any omission or description in an identification report or a grading report resulting from human error, defective instruments, delay or other defects in connection with the testing procedures, issuance or use of the identification report or the grading report, unless there is fraud or willful misconduct by GUILD or its agents or employees.


If a client fails to disclose all facts that are known by the client concerning the tested item for which the client requested identification and grading, GUILD and its employees shall be exempted from any and all loss, damage, or expense, etc. incurred as a result of identification and grading.


Conclusion on the identity and treatments of gemstones is an opinion of the labora

tory based on the direct comparison of the findings with those obtained from the analysis of reference materials, as well as those in published literature obtainable at the time of examination. As many mines around the world produce gemstones that display similar properties, an opinion on the most probable geographic origin of the examined gemstones cannot always be given. Unless expressly agreed otherwise, the client agrees not to hold GUILD liable for the loss or damage of the submitted gemstone (s) resulting from risks that may occur during the transportation and delivery process, including robbery and theft, during the examination process including alterations of all kinds including removal of fissure filling in the gem material; and while in the gemstone is in the possession of GUILD, including theft negligence and natural acts of god.


GUILD will re-issue certificates within a period of one year from the issuance of the origin certificates on customers' request. GUILD has the right to retain the items which are not collected or if the amount of certificates was not paid, within a period of 90 days after the article submitted to GUILD. The laboratory may refuse the issuance of a certificates at any time. GUILD and its employees and agents shall not be liable for any loss, damage or expense resulting from any error in or omission from this certificates or from the issuance of or use of this certificates, even if the loss, damage or expense was caused by or resulted from the negligence or other fault (except fraud, willful misconduct or gross negligence) of GUILD or any of its employees or agents, and in any event GUILD and its employees and agents shall not be liable for special or consequential damages resulting from any error in or omission from this certificates caused by the acts of others, even if advised of the possibility of such damages. All intellectual property rights belonging to GUILD, more particularly the contents of this Report / Certificate, the name, the design, trademarks, service marks and logos of GUILD shall not be used in whole or in part for any purpose whatsoever including for purposes of advertising, publicity or promotion and this report may not be referred to as a guarantee, valuation or an appraisal.



Expert Witness

Noted gemologist, appraiser and author Charles Carmona has extensive experience consulting for attorneys and has testified in numerous regional and national legal matters. He is frequently retained to provide advice in legal proceedings requiring specialized knowledge of industry practices and the valuation of jewelry, diamonds, gemstones, coins and currency, silver and related personal property.

An expert valuation specialist, Mr. Carmona's contributions are key to determining financial damages in complex litigation, criminal matters, insurance claims, class actions and other disputes.


Mr. Carmona is a Graduate Gemologist (GG) from Gemological Institute of America (GIA) with over 35 years of experience. He is also an Accredited Senior Appraiser (ASA) and past president of the southern California Chapter of the American Society of Appraisers.

His highly acclaimed reference book, The Complete Handbook for Gemstone Weight Estimation is relied upon worldwide by jewelry professionals as the authoritative source for estimating mounted gemstone weights by shape, dimension and specific gravity.

His professional opinions are frequently sought out by the media, and he's an oft invited speaker at special events, museum groups, at workshops and trade shows.


Mr. Carmona has earned an exemplary reputation as an impartial expert witness, assisting both plaintiffs and defendants.

He offers consultation and appraisal services for museums, accountants, and insurance companies, governmental and non-governmental agencies, including The World Bank, Interpol, Department of Homeland Security, IRS and Securities & Exchange Commission, among numerous others.

Clear and Persuasive Testimony

Mr. Carmona thoroughly understands the trial process and how to anticipate a line of questioning during cross examination.

He exhibits acute awareness of nonverbal cues like facial expressions, gestures, posture and eye contact, and how they contribute to juror perception.

He conveys clear, confident and concise testimony that underscores his persuasiveness and effectiveness.


Mr. Carmona delivers critical support to his clients at each stage of a legal dispute, from fact-finding and discovery to settlement or trial. His services include expert witness testimony, reports, critiques of opposing expert opinions, and consultation during discovery and fact-finding.
His expertise covers the following areas:

  • Accounting & Business Inventory Audits
  • Arbitration & Mediation
  • Commercial Damages
  • Complex Civil Litigation
  • Contractual Disputes
  • Criminal Litigation
  • Damage Estimates
  • Equitable Distribution
  • Fair Market Value (Estates, Gifts, Donations, Casualty Loss)
  • Family Law
  • Financial Investigations
  • Fraud and Mismanagement
  • Immediate & Orderly Liquidation Value
  • Insurance
  • Intellectual Property Disputes
  • Professional Malpractice