Emerald, a precious stone. It is of a peculiar green color. It is found in the form usually of a short, six-sided crystal. It is rather a soft stone, being little harder than quartz. An emerald is composed chiefly of silicon and aluminum. It contains a trace of glucinum. Its color is due to oxide of chromium. When heated, the emerald turns blue, but resumes its natural color again when cool. If heated too far, however, it melts into a white, clouded mass of no value whatever. The emeralds of the ancients were obtained from Ethiopia and Upper Egypt. They were greatly prized, both on account of their rich color and the ease with which they could be carved into desired figures. The finest emeralds of modern times have been obtained from Peru, Colombia, and the Urals. The largest emerald known is that in the Royal Museum at St. Petersburg. It was obtained in the Ural Mountains and weighs over six pounds. A magnificent emerald gem is kept with the crown jewels in the treasure chamber of the imperial palace at Vienna. In the language of precious gems, the emerald represents success in love. Ireland is called the Emerald Isle because it is usually clothed with beautifully green vegetation.