crystals grouped together with interspaces and cavities between them. The whole mass weighs probably over a hundred pounds.
The
mineral called "oligoclase" is the sodic variety and chemically not far
removed from albite in composition. It occurs in rough crystals, some
of which have perfect cleavage and measure several inches across. It is
mostly white, with small colorless patches, but exhibits a beautiful
pearly blue chatoyancy on one of the cleavage planes. In some specimens
this pearly luster is seen over areas several inches across when the
specimen is viewed in a favorable position. This oligoclase makes
beautiful cabinef specimens if properly exhibited and yields very
pretty gems when cut cabochon about parallel with the pearly cleavage.
Cut gems are white to mottled gray and show a fine blue chatoyancy in
one position.
Fontaine
desciibes a pocket 4 or 5 feet long and high and 1 to 2 feet wide
opened in pit No. 2 lined with numerous crystals of smoky quartz and
"pure white crystals of albite, some as transparent as glass."
Large
beryl crystals were found in pit No. 2, but few, if any, of gem
quality. Fontaine describes them as 3 or 4 feet long and as much as 18
inches in diameter, surpassed in size only by those of New Hampshire.
They were bluish green and dingy yellow and were associated with the
quartz and feldspar. The beryls were closely intergrown with the
feldspar, but they separated easily from inclosing quartz.
A
quantity of beautiful transparent spessartite garnet of reddish-brown
or hyacinth-red color was found during mining operations. This material
was cut for gems and also supplied many mineral collections. Some of
the crystals measured 3 inches in diameter and were composed of solid
garnet. The better stones came from opening No. 2. Watson states that
hyacinth gems were cut weighing from 1 to 100 carats.- Nine cut gems in
the United States National Museum range from 5.65 to 39.13 carats in
weight. These gems are rather lighter hi color than most zircon or
essonite garnet varieties of hyacinth. There is a marked shade of red
or pink in the brown which is thereby enhanced in beauty. All the nine
stones mentioned contain flaws; some of the nine are a little cloudy
from the abundance of these flaws, but others are transparent and
brilliant in spite of the few cracks. The gems exhibited in the Natuial
History Museum in New York show the same characteristics.
The
chlorophane variety of fluorite also occurs in the Rutherfoord mine and
according to Fontaine was found chiefly in pit No. 2. Some pale-purple
fluorite has also been found. This fluorite is not of value for
ornamental use but is of interest for the ease with which it
phosphoresces. G. F. Kunz 1 calls attention to the fact
that the mineral from this locality phosphoresces by attrition with
hard substances. In a dark room at 80° F. it glows with a white
luminous light. In boiling water it gives off a green light and on
heated iron an emerald-green light. These observations were confirmed
by tests made by the writer on a specimen supplied by Mr. Rutherfoord.
This specimen was grass-green and badly flawed. The surface was
strongly etched and corroded. The mineral glowed with a yellowish light
after continued heating when the intensity of the green began to fade.
i Chlorophane [rom Amelia County, Va.: Am. Jour. Sci., 3d ser., vol. 28, 1884, pp. 235-236.
