Aquamarine Post EarringsThese aquamarine trillions provide great sparkle and the clear, pale blue of the ocean on a warm day. The blue sapphire rounds just above the trillions are a lovely contrast that suggest flashes of a darker blue in the water. These are extremely dainty post earrings. The aquamarines are 4 mm in diameter, and the sapphire rounds are 3 mm in diameter. The setting is sterling silver with a patina of 22 karat yellow gold. Aquamarine is the birthstone for