Beryl (variety: Aquamarine)

Aquamarine is the sea-blue variety of the mineral beryl. Its color depends on the relative amounts of impurities of iron in two different chemical states (Fe+2 and Fe+3). Heating removes the green tones (by converting Fe+2 into Fe+3), resulting in a more pure shade of blue. The large crystal shown here weighs 15,256 carats (131 kg or 6.7 lbs). Its near perfect shape and few internal flaws indicate that it grew in ideal conditions. Large aquamarine crystals of this quality and color are rarely preserved; usually they are cut in to gems.

Beryl (variety: Aquamarine)

Aquamarine is the sea-blue variety of beryl. Its color depends on the relative amounts of impurities of iron in two different chemical states (Fe+2 and Fe+3). Heating removes the green tones (by converting Fe+2 into Fe+3), resulting in a more pure shade of blue. This 1,000-carat, flawless stone is nicknamed "Most Precious" after a perfume created by its donors, Evyan Perfumes, Inc.