There are no true "synthetic" or "scientific" or "reconstructed" emeralds, and none of these terms should be used by the trade. There has been an effort made in some cases to do business upon the good reputation of the scientific rubies and sapphires, but the products offered, when not out and out glass imitations, have usually been doublets or triplets, consisting partly of some pale, inexpensive, natural mineral, such as quartz or beryl, and a layer of deep green glass to give the whole a proper color. All attempts to melt real emerald or beryl have yielded only a _beryl glass_, softer and lighter than true emerald, and not _crystalline_, but rather glassy in structure. Hence the names "reconstructed," "synthetic" and "scientific" should never be applied to emerald. The light green and blue green beryls are correctly called _aquamarines_, the pale sky-blue beryls should be named simply _blue beryl_. Yellow beryl may be called _golden beryl_, or it may be called "_heliodor_," a name that was devised for the fine yellow beryl of Madagascar. Beautiful pink beryl from Madagascar has been called "_morganite_," a name that deserves to live in order to commemorate the great interest taken by J. Pierpont Morgan in collecting and conserving for future generations many of the gems in the American Museum of Natural History in New York. ZIRCON. We now come to a number of minerals slightly less hard than beryl, but harder than quartz, and _zircon_ is perhaps as hard as any of these, so it will be considered next. Red zircon, which is rare, is properly called "_hyacinth_." Many Hessonite garnets (cinnamon stones) are incorrectly called hyacinths, however. The true hyacinth has more snap and fire owing to its adamantine surface luster and high dispersive power, as well as to its high refractive index. A true hyacinth is a beautiful stone. Golden yellow zircons are correctly called "_jacinths_." Artificially whitened zircons (the color of which has been removed by heating) are known as "jargoons" or sometimes as "Matura diamonds." All other colors in zircon should be named simply zircon, with a color adjective to indicate the particular color as, "brown zircon," etc. TOURMALINE. Tourmaline furnishes gems of many different colors. These are all usually called simply tourmaline, with a color adjective to specify the particular color, as, for example, the "pink tourmaline" of California. Red tourmaline is, however, sometimes called "_rubellite_," and white tourmaline has been called "_achroite_." The latter material is seldom cut, and hence the name is seldom seen or used.