About ZGL
Founded and led by Dylan Tilley since 2013, the Zenith Gemological Laboratory has grown from a small, independent jewelry shop and appraisal service to a widely connected and established presence in the United States, serving thousands of happy clients and continuing to grow and improve our equipment and techniques to better serve your needs every year.
We are members of the GIA alumni association, Gemworld International, Global Claims Associates, and several more that can be viewed at the bottom of the page. These organizations have talented communities and various continuing education requirements, industry news, and quality guidelines that keep their members at the top of their game, and ensure that our clients receive the industry’s best possible service, with the most accurate knowledge and techniques available today.
Our mission is not only to serve the industry’s daily needs, but to promote the sharing and curation of knowledge, so that our colleagues, and even our competitors, will naturally improve.
Along with our many individual customers, some of our business clients include;
Sergio’s Fine Jewelers
Starfire Designs
A&M Jewelers
JRC Jewelry center and gift boutique
Antiques On the Go
del Cuadro-Zimmerman PLLC Attorneys at Law
JZ Williams Attorney at Law
U.S. General Services Administration
Federal Bureau of Investigation (FBI)
CF Brandt Jewelers
Carlson’s Jewelers
Helzberg Diamonds
TNT Jewelers
Jewelry Place by the Bay
Bright Jewelers Corporation
Dynasty Casting and CAD
Savage Designs
Calico Mall Antiques
RA Goldsmith
Diamond Dust International
Tribal Gems International
Prince George’s County Police Department
…And several more we can’t list here.
Founder, Dylan Tilley
A dedicated scholar, Dylan is a 4th generation jeweler, watchmaker, gemologist and appraiser with over two decades of industry service, learning and working under masters of several different fields. A significant portion of his time is spent performing and sharing in-depth research and educating other gemologists and appraisers.
Having stepped away from high level jewelry and watchmaking to focus entirely on the Zenith Gemological Laboratory, his goal is to grow a long lasting, industry leading gem lab, appraisal service, and educational facility in the Baltimore/Washington DC area, and to continue learning and perfecting every aspect of the business for years to come.
Industry Experience:
Founder and CEO, Zenith Gemological Laboratory, 2013-Present
Founder and CEO, Elite Jewelry and Time, 2018-2022
Store Manager/Multi Unit, Helzberg Diamonds, 2016-2018
Senior Management Consultant for various businesses, 2017-present
Founder, Little Wing Enterprises, 2013
Director of Services, Midwest Manufacturing, 2011-2013
Jeweler/Gemologist/Watchmaker, Cody Consultants for various corporate and independent entities on short contracts from 2007-2011
Apprentice Jeweler and Watchmaker at family stores; Falcon’s Jewelry, Clyde’s Jewelry and Watch repair, Master Jewelers, 1997-2007
Volunteer Work:
Volunteer Astronomer, Smithsonian Center for Astrophysics at Harvard University, 2015-2019
Volunteer Astronomer, Science Mission Directorate at NASA, 2015-2019
Volunteer Staff/Young Einstein program, Mid America Science Museum 2001-2009
Non-certified Training and Audited Courses:
Gemmological Association of Great Britain, 1987 Preliminary courses P1 and P2, Diploma courses D1 and D2 AUDITED with full physical course texts on file for reference. (These are the Gem-A’s old FGA courses)
American Gem Society, 1991 and 2009 “The AGS Way” courses AUDITED with full physical texts on file for reference.
World Gem Foundation, 2021 Career Gemologist and Diamond Professional courses AUDITED with full digital course texts on file for reference.
Patuxent Lapidary Guild 2019 Diamond and Colored Gemstone lapidary training. No diplomas provided.
Professional Coin Grading Service
Coin Grading 101, 102, and 103. No diplomas provided.
Alec Steele’s School of Blacksmithing 2019 Intermediate Blacksmithing and Evolution of Tool Making courses. No diplomas provided.
