exposure to radium rays. On warming and sprinkling them with flour of sulphur and red lead (the sulphur clinging to the electropositive and the red lead to the electronegative parts of the quartz twin) the smoky tint was developed in three triangles (segments of one of the twins), which were found to be negatively electrified. This study has been described by M. P]geroff.a A related question of equal interest concerns the nature of the smokiness that is thus eliminated and redeveloped. It has usually been supposed to be carbon, but it may prove to be something quite different, as it is not easy to see how a carbon compound could thus be affected.
NONCRYSTALLINE QUARTZ.
CHALCEDONY.
A number of occurrences of beautiful varieties of chalcedonic quartz minerals have recently been reported to the writer. Most of these are on the Pacific coast, but several are in other parts of the country.
IOWTA.
A beautiful gray and fawTn-colored translucent chalcedony, in rolled botrvoidal masses, up to 3 inches by 2 by 2 in size, has been found in the vicinity of Ames, Iowa, by Mr. H. B. Jones. These pieces are rich in color, very compact, and would answer for some forms of ornamental work.
OREGON.
S<ij)j>li!riiic chalcedony. In the vicinity of Eaglepoint, Jackson County, Oreg., a great quantity of beautiful chalcedony, agate, and jasper has been found. Among these are some beautiful white chalcedony, gray, brown, and green jasper, and an endless variety of agate. Of especial interest, however, is a beautiful blue chalcedon}T (sapphirine), which is quite equal to that found in Hungary or in California.
NEVADA.
Rose chalcedony. A most beautiful rose and lilac-tinted variety of chalcedony is reported from Aurora, New, by Mr. Maynard Bixby, the" well-known mineralogist of Salt Lake City, Utah. It occurs "in iin amygdaloidal rock, and the delicate rose-pink variety, very translucent, rests directly upon a base of almost white chalcedony. Where broken across, the fractured surface shows'a peculiar almost stellated structure.
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