Diamond demand is high, but supply is lowThe U.S. gemstone market is in the midst of active trading. Diamonds continue to be strong, with some dealers questioning whether current prices are sustainable. More dealers are reporting resistance to prices in the finer-quality rounds. However, supply is still short in many categories and consumption remains strong in overseas markets; therefore, there is no reason to expect the trend toward higher prices to ease. The Rapaport Group estimates that average DTC rough prices have increased 35 percent during the first six months of this year. Polished prices have been under pressure for some time now to rise and bridge the large gap that exists between rough and polished. U.S. diamond sales remain centered on bridal.In the colored stone market, dealers are reporting that well-cut traditional gem varieties are selling well. Blue sapphire is outselli