Beryl over , and its dimensions were long and in diameter. The largest cut aquamarine gem is the Dom Pedro aquamarine, now housed in the Smithsonian Institution's National Museum of Natural History. The ancient Romans believed that aquamarine would protect against any dangers while travelling at sea, and that it provided energy and cured laziness. Emerald is green beryl, colored by trace amounts of chromium and sometimes vanadium. Most emeralds are highly included, so their brittleness (resistance to breakage) is classified as generally poor. The modern English word "emerald" comes via Middle English "Emeraude", imported from modern French via Old French
Gemstone characteristic that lends value to a gemstone. Apart from jewelry, from earliest antiquity engraved gems and hardstone carvings, such as cups, were major luxury art forms. A gem maker is called a lapidary or gemcutter; a diamond cutter is called a diamantaire. The traditional classification in the West, which goes back to the ancient Greeks, begins with a distinction between "precious" and "semi-precious"; similar distinctions are made in other cultures. In modern use the precious stones are diamond, ruby, sapphire and emerald, with all other gemstones being semi-precious. This distinction reflects the rarity of the respective stones in ancient times,