Mission Our jewelry represents the most flawless techniques and exquisite designs. Award winning custom designs are masterfully handcrafted in-house by our Designers and Platinumsmiths utilizing state–of-the-art technology. Company Overview Welcome to Charles Koll Jewellers. We are a proud member of the American Gem Society (A.G.S.), symbolizing the most exemplary ethical standards of business. We are San Diego's premier diamond source. We feature an exclusive collection of Designer diamond engagement rings as well as custom created diamond jewelry. For 58 years, we have been committed to perfecting the ultimate combination of creativity and technical achievement. We believe that quality should never be compromised. Each exquisite jewelry design is selected with this philosophy in mind.