The bangle above is reverse-carved and painted in the areas that are carved. In a process called called vapor deposition, the quartz is put into a vacuum chamber and attached to very hot electrodes. Today, blue aquamarines are more highly valued, but this was not true in the past, when sea-green stones were prized. Heat-treatment turns greenish stones bluer. The best aquamarines come from Brazil.
Large aquamarines are relatively common.
Aquamarines are usually faceted but when they are cabochon cut, a cat's eye effect or asterism may appear. Aquamarines belong to the beryl family of stones. It is transparent to translucent and can range in color from honey-colored to pale reds, blues and greens to clear or white. It forms hexagonal crystals, pyramidal crystals, chisel shaped crystals, and other shapes. Aragonite is named for Aragon, Spain, where it was first found in 1790.