The Ceylon moonstone is sometimes known as Ceylon opal, but it is the variety of Feldspar known as orthoclase, which is a potash Feldspar, differing from the microcline just described in being monoclinic in crystallization and in having two cleavages meeting at right angles. Another species of Feldspar used as moonstone is albite. This is a soda Feldspar and is triclinic, but exhibits the color characteristic of moonstone. One variety is known as peristerite, from the Greek word for pigeon, and is applied on account of the resemblance of the sheen to that of a pigeon’s neck. It is found at Macomb, St. Lawrence county, New York. Albite found at Mineral Hill, Pennsylvania, also exhibits the chatoyancy of moonstone. Amelia Court House, Virginia, is another locality whence come pieces either of orthoclase or oligoclase exhibiting this property. Like most of the more or less opaque gems, moonstone is cut chiefly in the rounded form known as en cabochon. It is of late, however, cut in the form of balls, which are quite popular, the bringing of good luck being attributed to them. The brilliancy of moonstone is considerably increased by mounting it against black. Sunstone is the term by which those kinds of Feldspar are known which reflect a spangled yellow light. The appearance comes from minute crystals of iron oxide, hematite or gothite, which are included in the stone and both reflect the light and give it a reddish color. Like labradorite the sheen is visible only when the stone is held at a certain angle. Some specimens of the mineral carnallite, which is a chloride of potassium and magnesium, exhibit a similar sheen, and being soluble in water the crystals of hematite can be separated out. They are then seen to be perfect little hexagons of a blood-red color. The sheen of sunstone is best visible when the stone is held in the sunlight or strong artificial light. The variety of Feldspar to which the sunstone most in use at the present time belongs is oligoclase, a soda-lime triclinic Feldspar. Like labradorite it usually exhibits on the surface of easiest cleavage parallel striations due to twinning structure. The best sunstone at the present time comes from Tvedestrand, in southern Norway, where it occurs in compact masses together with white quartz, in veins, in gneiss. Some also comes from Hittero, Norway. In Werchne Udinsk, Siberia, another occurrence was discovered in 1831. Previous to this Bauer states that all the sunstone known came from the Island of Sattel in the White Sea, and was very costly, although of a quality which would not now be deemed desirable. At the present time, although stones of fine quality can be obtained, sunstone is little used in jewelry, and its market value is very low. Statesville, North Carolina, and Delaware county, Pennsylvania, are two localities in the United States where good sunstone has been obtained.