Specializing In GIA Certified Natural Fancy Colored Diamonds... Jewelry Bankers is one of the nations largest providers of Rare and Significant Fancy Colored Diamonds. Supplier to some the world’s most recognized names in jewelry retail, we procure our diamond inventory directly from sight holders and cutters from around the world. Due to the rarity of “Colored Diamonds,” and knowledgeable dealers alike, our expertise in this niche area, certainly lends itself to an enjoyable and truly educational experience for our clientele.