be
more like jasper. In places the chalcedony grades into crystallized
quartz. The material occurs in masses and aggregations of spherulites
with mammillary and botryoidal structures. The spherulites range from
minute size to over a centimeter in diameter and show a beautiful
concentric agate banding of thin gray, white, and red layers. A
radiated texture may or may not be visible and in some spherulites tiny
radial quartz crystals occur in the center or in la}Ters. A
few of the spherulites exhibit very little internal structure or merely
have spots of red near the center surrounded by gray chalcedony with
even texture. In some specimens the spherulites are large or a number
have been cemented together by chalcedony so that stones of sufficient
size for cutting are obtained. Some of the gems are said to give the
effect of thomsonite with deep jasper-red tints in gray matrix. As
small fancy agates some of the larger spherulites would be very
effective.
In
some specimens spherulites of various sizes are thickly distributed
through granular crystallized calcite. Many of the spherulites are
isolated but some are bunched in botryoidal masses as shown when the
calcite gangue is dissolved by acid. One specimen is described as
resembling the cast of an ammonite shell. It was not
p
ossible to determine
the nature of this from the sample submitted. It consisted of many
spherulites cemented together with chalcedony with cavities lined with
small crystals of quartz and calcite. The sample examined evidently
came from a disklike specimen about 2 inches thick.
OREGON.
Chalcedony,
agate, and jasper-like agate have been found near Rogue River and Eagle
Point, and for some distance along Rogue River valley. The chalcedony
is translucent and gray with a slight agate banding, and is found in
streaks and nodules in the basalt near Ashland. Some of it contains
cavities lined with quartz crystals. The agate is varicolored, ranging
from banded translucent gray to mottled red and yellow, and some of it
contains so much iron oxide as to resemble jasper. Two specimens
labeled "red moss jasper" consist of opaque and translucent chalcedony
crowded full with dark-red, reddish-yellow, and yellow mosslike
markings of jasper. In other specimens of moss agate there are black to
dark-brown spots and dendrites. One specimen found near the town of
Klamath Falls consists of rather cloudy red chalcedony or agate,
inclosing streaks and spots of gray and white chalcedony.
AMETHYST.
NORTH CAROLINA.
The
occurrence of amethyst at several places in the vicinity of Raleigh, N.
C, has been reported at different times by L. A. Fort, of that city. An
opportunity was given to the writer to examine one of these deposits on
the land of George W. Partin, 5 miles northeast of Raleigh. Here
amethystine quartz and pale amethyst crystals are found on the surface
of a cultivated upland field. Three or four small prospect pits, now
filled up, had been made a few years ago. The deepest of these pits was
about 9 feet, at which depth the rock was less decomposed than near the
surface and hard to excavate.
