As the trade preps for the warmer months, prices, supplies, and colors are top of mindRetail jewelers are optimistic that consumers will continue to return to the market and, as such, are buying for stock in growing numbers. The trend is solid, but much of the activity is centered on bridal. In diamonds, well-made round brilliants are difficult to find in larger sizes. This is reflected in the string of polished price increases observed during March and early April. With shortages still being reported, the trend toward higher prices is gaining traction.In the colored stone market, dealers report that blue sapphire is in good demand. In particular, fine quality, cushion-cut natural sapphires lead the market. Other good sellers this spring have been purple sapphire, blue zircon, aqua­marine, red tourmaline, blue spinel, and emerald. Demand for pink sapphire remains softer than in recent y