DercDerco Jewelers is committed to providing top quality diamonds and jewelry at exceptional prices, with a dedication to service unsurpassed in the industry. Established in 1939 with founder Krikor (Koko) Der Abrahamian and headquartered in San Francisco since 1979, Derco has a loyal, discerning customer base centered in the Bay Area that extends across the country and throughout the world.o Jewelers is committed to providing top quality diamonds and jewelry at exceptional prices,