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.


Pitchaya Lopiti

Pitchaya graduated with a degree in material science (gemmology) from Srinakharinwirot University in Thailand. Her studies included gemmology, jewellery making and production, jewellery design, illustration and CAD/CAM. After graduation, she worked as a sales executive and customer service representative for Malca-Amit Co., Ltd, a transport company for precious goods. She also worked in sales for an upmarket jewellery company. Pitchaya is now an instructor at GIA in Bangkok, where she teaches the Diamond Grading, Coloured Stone Grading and Gem Identification lab classes, as well as the Accredited Jewellery Professional and Graduate Coloured Stones diploma programmes. Pitchaya's background in material science and gemmology, along with her work in the jewellery industry make her a valued resource for her students. She particularly enjoys sharing ideas and engaging in conversations with them.

Panissara Navasamakkarn

Panissara earned her bachelor's degree in science (geology) from Chulalongkorn University. Her studies included gemmology, mineral deposits and geotectonics. After she graduated, she worked as a diamond grader for GIA in Bangkok. She excelled at this precise and demanding work and was hired as an instructor, where she now makes use of her college education and lab experience. Panissara aspires to help her students excel in their studies so they can have successful careers.

Piyapratch Poonsilp

Piyapratch graduated with a bachelor’s degree in biology from Chiang Mai University and with a master’s in chemical biology from Chulabhorn Graduate Institute. He then taught science and chemistry at high school and undergraduate levels. After earning his Graduate Gemologist diploma, Piyapratch joined GIA in Thailand in 2015 as an on-campus instructor. With his education background and teaching experience, Piyapratch is an excellent resource for students seeking gemmological and scientific knowledge. His dedication and efforts ensure GIA students can accomplish their goals and succeed in their careers.

jewellery manufacturing arts

Ninnate Plumkratoke

Ninnate graduated with a bachelor's degree in material science (gemmology) from Srinakharinwirot University. Her studies included gem identification, jewellery design, jewellery making and marketing. Ninnate also received a master’s degree in contemporary jewellery design from Silpakorn University, Thailand. During her studies, she worked as a part-time jewellery designer for a company that exported pieces to the Middle East. After graduation, Ninnate worked as a freelance jewellery designer for a jewellery company and in marketing and design for a diamond manufacturer. She teaches the Jewellery Design and Quick Design courses at GIA in Thailand. Her goal is to inspire students to create their own style. Ninnate loves working closely with her students and sharing perspectives on design.