Yosef Caldaron (Josef C) is a gemologist, renowned advisor to important collections, and purveyor of diamonds and jewels, who is based in NYC's Diamond District.

A graduate of the Cornell School of Hotel Administration, Josef C infuses hospitality into the diamond business, where he consistently exceeds client expectations. He gained extensive technical expertise by studying at the Gemological Institute of America (GIA) where he earned the Graduate Gemology degree (GIA GG), Additionally, he completed the diplomas in Gemmology and Diamonds from the Gemmological Association of Great Britain (Gem-A), earning him the credentials Fellow and Diamond Member of the Gemmological Association of Great Britain (FGA & DGA); the FGA and GIA GG credentials are the two most highly regarded gemological degrees in the world.

Yosef previously worked as a diamond grader at the GIA Laboratory in Ramat Gan, Israel, after completing the industry's most intensive diamond training program; and developed a special eye for quality, detail and craftsmanship while working at Tiffany & Co. in New York City. A member of the National Association of Jewelry Appraisers (NAJA), he is currently the only Certified Master Appraiser in New York.