As the only AGS-certified jeweler in San Jose, and one of less than a dozen in the South Bay Area, Willow Glen Diamond Company takes great pride in our long-standing commitment to highest standards of business practices and ethics so that you can buy with confidence. Beyond a simple diploma or academic credential, being a member of the AGS means taking yearly certification courses and testing, and agreeing to be bound by the ethical practices defined by the trade organization, including not to sell conflict diamonds, provide full disclosure on all products we sell, and continuing our gemological and jewelry education to keep up with trends and technology in the jewelry business. Diamonds.