GIA instructors are passionate educators who bring years of industry experience to the classroom. All are leaders in their fields, and all are dedicated to helping you gain knowledge, acquire skills and launch your career.


John Cason

John is the supervisor of on-campus gemology instruction and joined GIA with more than 14 years of diverse jewelry industry experience, including diamond buying trips to Antwerp, jewelry sales, and jewelry manufacturing. After more than ten years in the trade, John received his GIA Graduate Gemologist® diploma. He also has education credentials in multi-media technologies and jewelry manufacturing and design. In his spare time, John received his Instructor Certification from the United States Power Squadron in Oceanside, California and he enjoys teaching safety and sailing skills.

Martin Harmon

Martin’s career in the jewelry industry began with an art class in high school and continued in college. In 1982 he attended GIA in Santa Monica, completing the Graduate Jeweler and Graduate Diamond diploma programs. He also earned the Colored Stones and Gem Identification diplomas through Distance Education while working full time. Martin’s trade experience includes 16 years in the retail industry and 12 years in management, with stints working as a bench jeweler, production manager and buyer in the wholesale industry. Martin started as an instructor for the on-campus Graduate Gemologist® program at the Carlsbad campus in May 2000, and then worked in the GIA Laboratory as a staff gemologist, diamond grader and quality assurance grader. For Martin, the most rewarding part of being an instructor is helping students achieve their goal of becoming a Graduate Gemologist®.

Brenda Harwick

As senior manager of on-campus instruction at the Carlsbad campus, Brenda's experience is a product of her more than 10 years of demonstrated knowledge of the theory and practice of diamond grading, colored stone grading, and gem identification. Brenda’s expertise comes from extensive retail and formal gemological training. Her passion for gems and jewelry, her keenness to absorb product knowledge, and her flair for customer relations propelled her to a successful career in retail that included positions in sales, buying, and preparation work for custom jewelry design and manufacturing. Her love of gems and jewelry brought her to GIA, where she earned her Graduate Gemologist® diploma. Brenda was hired as an on-campus instructor at GIA Carlsbad in 1999. She has also taught at several GIA campuses around the world.

Jessica Kramer

Jessica’s interest in gemology started late in high school, which led her to attend GIA and earn her Graduate Gemologist® and Applied Jewelry Professional diplomas in 2005. She spent ten years in retail jewelry sales, selling engagement rings and fine jewelry, and worked closely with jewelers creating custom pieces for their clients. Jessica joined the GIA laboratory in 2015 as a staff gemologist, with diamond grading as her chief responsibility. She later helped train new diamond graders and gave lab tours to students and clients. Since joining the education team as a gemology instructor, Jessica has been able to merge her passions for diamonds and gemstones, while helping and teaching her students.

Carson Lee

Carson started in the jewelry industry as a goldsmith. His more than 10 years of work experience also includes: sales of fine watches and jewelry, sales training, and jewelry design. Carson enjoyed working closely with his customers in providing service excellence in repairs, sales, and custom designing jewelry. Prior to his work in the trade, Carson spent two years in Brazil; as a result, he is fluent in the Portuguese language.

Tim Richardson

Tim started in the jewelry industry at the age of 15, learning basic repair and polishing in his family’s jewelry business. At age 17 he started working in sales, gaining experience in engagement jewelry, fashion, appraisals and custom design. After earning a Bachelor’s degree in Business Administration and Music Liberal arts in 2012, Tim took on the role of store manager. During this time, he enhanced his sales experience, attended trade shows and earned his Applied Jewelry Professional credential. Upon graduating from GIA in Carlsbad in 2014 with a Graduate Gemologist® diploma, Tim began working as a staff gemologist/diamond grader in GIA’s diamond grading laboratory. He joined the Education team as an instructor of gemology in 2015.

Nina Switzer-Spano

Nina had been working in the jewelry trade for four years when she realized that earning her GG credential would significantly advance her career. After graduating from GIA, she worked for 11 years at Bergmann’s Fine Jewelry as manager and appraiser. She joined GIA as an instructor in 2007, bringing her experience and in-depth knowledge of selling, designing, and buying jewelry to the classroom.

Teresa Tolbert

Teresa’s passion for gems and jewelry led her to GIA’s Graduate Gemology program in Carlsbad. After graduating with the GIA Graduate Gemologist® and Applied Jewelry Professional diplomas in 2005, she began working in the GIA laboratory as a diamond grader, color grading diamonds in the D-Z range as well as Fancy colored diamonds. For a significant part of her 14-year tenure in the lab, she helped train new diamond graders in Carlsbad, New York, India, Israel and Botswana. She also took on a number of other roles, such as quality assurance. One of the most rewarding aspects of her work was watching the advancement of the graders she trained. Her desire to help the next generation of gemologists led her to become a Gemology Instructor at GIA.

Kate Trunnell

Before joining GIA in 2005, Kate did bench work and design for a glass artisan for six years. She also worked for several years as a jewelry parts supplier. Kate’s experience in jewelry retail, wholesale, and design gives her a unique understanding of the art of creating jewelry from start to finish. Kate shares her feelings about working at GIA: "I like being a part of the joy and pride that students have for themselves once they accomplish their goals."

Shelly Verwymeren

A 14-year veteran of the jewelry industry, Shelly’s experience includes retail management, sales, jewelry design, and purchasing for a leading jewelry company in the United States. Shelly now works as a GIA Lab class instructor, and thoroughly enjoys teaching the fundamentals of gemology. Before becoming a gemologist, Shelly was an accomplished musician and music teacher. She operated her own entertainment company and worked in several European and Asian markets. While in Asia, Shelly worked for a Hong Kong-based jewelry company, where she specialized in international sales and marketing.

Kate Waterman

Kate has worked in the gem and jewelry industry since 2000 and joined GIA in 2011. Her passion for Mother Nature’s awe-inspiring creations inspired her to work in many areas of the trade, including: sales, management, operations, apprenticeship, goldsmithing, jewelry design, diamond grading, diamond research analytics, and she has now found her calling as an instructor of gemology. Kate earned her Applied Jewelry Professional certificate, and Graduate Jeweler, and Graduate Gemologist® diplomas from GIA and thrives in an educational environment. As she puts it: “Sharing my love of gemstones with students and watching them learn inspires me on a daily basis.”

jewelry manufacturing arts

Darla Alvarez

Darla spent the first two years of her career in jewelry sales, earning her Applied Jewelry Professional diploma, but was quickly drawn into the world of jewelry creation. After completing the Graduate Jeweler program, she worked in a trade shop for two years before being recruited by a custom design jewelry studio. She spent the next seven years absorbing everything there is to know about being a custom jeweler, learning all phases of repair, casting, fabrication, setting, and especially CAD/CAM. Darla joined the GIA team to share all of those real-world experiences with students to best facilitate their future growth.

Manuel Basmajian

Manuel’s passion for creating jewelry started in his youth, when he apprenticed at a manufacturing company that produced hand-crafted tennis bracelets. At the age of 16, he started working for a firm that specialized in CNC-machined wedding bands. He then worked in retail shops as a bench jeweler and retail sales. In 2002, he became the factory manager and CAD/CAM designer for a manufacturing company that specialized in the production of diamond and colored stone jewelry. In 2009, Manuel became the director of design for a company that created award-style military rings. He also created custom-model designs for leading jewelers. Joining GIA in 2016 as a new CAD instructor, Manuel brings more than 23 years of experience in the industry and a love for helping others.

Paula Carter Andrews

Paula joined GIA in 2015, instructing at the London campus before coming to Carlsbad in early 2019. After studying jewelry design and manufacturing at London Guildhall University, she began her professional career as an apprentice silversmith and goldsmith, which has evolved into an 18-year passion. Within the last nine years, her role has progressed to working on bespoke and CAD designs using the latest cutting-edge technology. Paula has gained a wealth of knowledge from her years in the jewelry industry, which she is keen to bring to GIA.

Jerry Golech

Jerry’s career in the jewelry industry began in 1983 in jewelry sales and sales management. His love of working with his hands led to a position managing a regional jewelry repair shop of a national retailer. In 1985, he opened a custom jewelry shop in Canton, Ohio, where his work included jewelry repair, fabrication, wax carving, casting and complex jewelry restoration work. Jerry joined the GIA education team in 2005 as an instructor in the Graduate Jeweler program. A GIA Graduate Gemologist® and lifetime learner, Jerry is passionate about informing and inspiring future generations of jewelers through classroom instruction and the development of course content.

Doug Hall

Doug first began making jewelry in 1973. With experience in everything from blacksmithing to diamond setting, he brings an impressive set of artistic, technical, and academic skills to GIA. He has a Bachelor of Fine Arts degree in metalsmithing from the Cranbrook Academy of Art, and has studied diamond grading and colored stone grading at GIA. Doug has conducted technical training at GIA’s laboratories around the world, and brings a wealth of experience to his students.

Don Hughes

Don’s path to the jewelry industry began with an interest in lapidary arts and silversmithing. In 1992, he completed the GIA Graduate Jeweler & Graduate Gemologist® programs. Before joining GIA staff in 2000, he ran a shop undertaking retail sales, custom design and bench work for seven years. He has taught extension classes in casting, rubber mold making, advanced stone setting and teaching the jewelry manufacturing arts process. Don is passionate about teaching and inspiring future generations of jewelers through classroom instruction of course content.

Michael Turinetti

Michael started in the jewelry industry as an apprentice at a family owned jewelry store. While there, he reconstructed vintage jewelry. He then went on to manage trade shops specializing in repair, and large companies that had a focus on manufacturing and high production of new products. Michael earned a Senior Bench Jeweler Certificate from Jewelers of America.Teaching jewelry manufacturing is a passion of his that he discovered many years ago.

Javier Zavala

Javier apprenticed to a local jeweler as soon as he graduated from high school. He continued his path of self-study and apprenticeship by working closely with goldsmiths Lance Frank and Isauro Martinez, and by attending numerous weekend seminars. Javier then spent 15 years running his own shop, where he specialized in repair and custom work. He also developed expertise in CAD/CAM and milling. Now he is eager to share his experience with GIA students.