Hallmark Research Institute
  Providing Education and Resources for a Better Understanding and Recognition of Precious Metal Hallmarks Worldwide

Author Bios

Danusia Niklewicz, GG, FGA, ISA-CAPP, ASA educator, appraiser, gemologist, jeweler, goldsmith. Ms. Niklewicz has been involved in the jewelry industry for over forty years. From retail bench jeweler to Graduate Gemologist (GIA), she earned her Fellowship from the Gemmological Association of Great Britain (GA) while a part of the Gemological Institute of America domestic and international teaching staff. From there, Niklewicz turned her focus to valuation by earning titles from the International Society of Appraisers (ISA) and the American Society of Appraisers (ASA), to become a respected independent jewelry appraiser to the antique and high-end jewelry community in Los Angeles for over thirty years. Ms. Niklewicz continued teaching and creating appraisal seminars for GIA, ISA and Insurance Education Association (IEA). Currently, Danusia Niklewicz and William Whetstone conduct an interactive lecture series on hallmarks of precious metals to industry professionals and collectors across the USA, Canada and abroad. Niklewicz brings to this publication her years of experience in jewelry, researching, course writing, international relations, graphics, and visual arts to co-write these narrative publications with the goal of providing a better understanding of hallmarking through methodology and imagery.


William Whetstone - historian, antiquarian jeweler, numismatist, educator, goldsmith. Mr. Whetstone has been a dealer and collector of ancient and world coins, as well as precious metal objets d’art for over forty years. A graduate with honors in history from McGill University, Mr. Whetstone was a former director and twice past president of the International Society of Appraisers (ISA), where he wrote the first technical Canadian course for professional personal property appraisers, lecturing on various topics in gems and jewelry, and residential contents and fine arts, both in the USA and Canada. Whetstone, who has been teaching the analysis of hallmarking for the past fifteen years, joined with Danusia Niklewicz and Lindy Matula to bring his years of expertise as a historian in analyzing, researching, and documenting world hallmarks to co-write these comprehensive publications.


Lindy Matula, GG, ASAappraiser, educator, gemologist, jeweler, goldsmith. Ms. Matula has been involved in the jewelry industry for nearly thirty-five years. Matula worked as a goldsmith prior to receiving her Graduate Gemologist degree from the GIA. Through the years Ms. Matula has been involved in the jewelry industry as a goldsmith, an investment diamond grader, wholesaler, appraiser, contemporary jewelry gallery manager, and instructor at the Revere Academy. Following her position as head gemologist for Butterfield's & Butterfield’s auction house, she aligned professions with Danusia Niklewicz in 1990 to create the networking appraisal group, Paradise Associates. Matula is currently the top independent appraiser of antique, contemporary and fine high-end jewelry in the San Francisco Bay Area. Co-writer Lindy Matula brings orchestration to this massive, multi-year project that has been vital to the completion of these publications in a series of volumes designed to lift the veil of complexity on modern and historic hallmarks.


Niklewicz, Whetstone, and Matula are the Founding Directors of the Hallmark Research Institute (HRI), and dedicated to furthering the understanding of precious metal hallmarks from around the world. Along with their research, HRI conducts lectures and educational seminars on hallmarks and are advocates for the promotion of global hallmarking.



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