Weldon served as the director of GIA’s RTL Gemological Library in Carlsbad. He positioned the library to be a critical archive for researchers, students and the trade, but also a significant content producer. Weldon is the recipient of the 2020 Antonio C. Bonanno Award for Excellence in Gemology.

As a photographer and writer and for Gems & Gemology, GIA’s scholarly publication, and more recently for Somewhere In the Rainbow, Robert handles and photographs superb, global, gemological treasures. Using his gift for photography and storytelling, he often writes feature, peer-reviewed articles for the journal. His images have enriched numerous articles in G&G and other publications and books. He counts over 40 covers of the journal to his name.

Weldon has been involved in the production of several books, including Splendour & Science of Pearls, which he co-authored and edited. A Rough Guide for Artisanal Miners is an educational book which he has also delivered and lectured on to artisanal miners in East African countries.

Robert and his wife, Orasa, are actively photographing and documenting the Somewhere in the Rainbow Collection.