the
blue chatoyancy remarkably well. It is there called "moonstone," and
may well be classed under this head, for it has the chatoyant effect
and in appearance differs but slightly from ortho-clase moonstone. The
greenish-gray granular albite or oligoclase found in the serpentine at
the magnesia quarries, West Nottingham Township, Chester County, Pa.,
shows a faint blue moonstone lustre. The beautiful feldspar found by W.
W. Jef-feris.with the sunstone at Pearce's paper mill, shows a blue
chatoyancy as marked as that of any labrador spar. It may be the
latter, or perhaps oligoclase. The finest examples of this material,
very closely resembling that from Ceylon in quality, transparency, and
color, and forming gems 1/2 inch across, have been found at the Allen
Mica Mines, Amelia Court House, Va. It also occurs in opaque pieces 6
to 8 inches square and of good color, showing a delicate blue
chatoyancy. Crystals an inch in length, of an opaque adularia feldspar,
showing a beautiful blue chatoyancy, are found on Mount Beckwith, Col.
Very good sunstone oligoclase, with fine reflections, has been found
near Fairfield, Pennsbury Township, Pa., also at Mendenhall's lime
quarries, Pennsbury, Chester County, and in Ashton Township, Pa., some
of a grayish-white colorwith coppery reflections ; and a curious
variety in moonstone (albite), showing double reflections. The green
and red sunstone found near Media, Pa., is very fine. In Middletown
Township, Delaware County, Pa., in one locality moonstone and sunstone
in small nodular lumps are scattered through the soil, and about a ton
of the material has been removed since its existence was discovered;
in another locality in the same township, moonstone is found in
boulders. A very fine sunstone, the orthoclase of which is of a rich
salmon color, quite transparent and streaked with white, showing the
aventur-ine effect beautifully, is found at Glen Riddle, Delaware
County, and another beautiful variety in the hornblende at Kennett
Township, Chester County, Pa. ; this Professor Genth thinks is
probably an oligoclase. Greenish orthoclase, sometimes in bright green
pieces, also pale green, and at times spotted with brownish tints, all
showing a sunstone effect, is found at Mineral Hill, Middletown, and
Upper Providence, Delaware County, Pa. The orthoclase of Frankford,
Pa., with gothite disseminated
