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PRECIOUS STOiYES.
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Moonstone. — It is no easy matter to class this chameleonlike gem, since it claims kindred with so many species, and
passes under so great a number of names. It constitutes a variety of orthoclase, albite, and oligoclase, all of the feldspar group, while the ancients applied the name to selenite or gypsum. It has been called cat's-eye, a name given to four other different stones ; argentine, a pearly lamellar calcite ; ceil de poisson (fish's eye) ; water or Ceylon opal, and adularla. The name hecatolite has been given to it for the same reason that it receives that of moonstone — namely, because it was thought to enclose the image of Luna, one of the forms of the threefold goddess Hecate. The moonstone of Dioscorides, which he calls moon-froth, was probably crystallized gypsum. This mineral exhibits a silvery or pearly light, not unlike
that of the moon, and in some of its varieties it resembles ice ; it is opalescent, white, grayish, yellowish, or reddish in color, and as an ornamental stone is very fashionable in some countries, where it is sold in large quantities. Moonstone of good quality, resembling that from St. Gothard, is found in Pennsylvania and Virginia, but the best variety comes from Ceylon, which yields some fine gems, known to measure more than an inch in length. Snnstone. — The aventurine oligoclase called sunstone exhibits prismatic reflections of a golden or reddish hue, the
result of minute disseminated crystals of hematite, gòthite, or mica, and is sometimes used for jewelry. The term aventurine applies to any mineral spangled with scales of some bright substance, and not to a species or to any particular variety of a species, — as aventurine quartz, aventurine feldspar; but sometimes the name is used in an indefinite manner, as when sunstone is called oriental aventurine. A variety of this mineral, from St. Gothard, passes under the name of adularla, which |
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