|
QUARTZ AND OPAL.
|
33
|
||
|
|
|||
|
sometimes
with great complexity (PL VI, A). They have furnished the subject for
several monographs on the crystallography of quartz, notably those by
Dr. Gerhard von Eath, of Bonn, and by Dr. Gill, of Cornell University.
Some of the large complex groups are very interesting from their
remarkable twinning-masses from 150 to 200 pounds, being made up of
many crystalline faces, while in general contour a single large
crystal. They stand quite unique as examples of beautiful color and
marvelous crystallization (see Pis. V and VI, A).
The
remarkable smoky crystals with included cavities, from Alexander
County, are referred to further on, under quartz inclusions.
Rose Quartz.—Specimens
of rose quartz from Dan River, Stokes County, N. C, show a beautiful
opalescence, and the existence of like quartz, as well as asteriated
quartz, in two other counties, Iredell and Cabarrus, was determined in
1894.
Quartz Inclusions (sagenite).—North Carolina has yielded more of this material for gem purposes than all other American localities together.
Rutilated
quartz of unexcelled beauty, the rutile brown, red, golden or black,
has been brought to light in many places in Randolph, Catawba, Burke,
Iredell, Jackson, and Alexander counties, especially the last, where in
1888 crystals of quartz, 3 inches in length, and filled with rutile the
thickness of a pin, were secured at Stony Point (PL V). Beautiful
series of these formerly in the collection of J. W. Wilcox, of
Philadelphia, are how in
the Morgan-Bement collection in New York. In 1901, fine rutilated
quartz, well crystallized and perfectly transparent, was developed,
together with handsome garnets, in the monazite mines near Shelby,
Cleveland County.
Hornblende in quartz is reported as found in Burke, Alexander, and Iredell counties.
Mining
operations at Stony Point, N. C, have brought to light a number of
crystals 4 by 3 inches, and masses of quartz 6 by 3 inches, some of the
former filled with what appears to be asbestos or byssolite, forming an
interesting and attractive material susceptible of being cut into
charms and other objects. Magnificent polished specimens are in the
Morgan-Tiffany and Morgan-Bement collections. The inclosures of what is
seemingly gothite in minute red, fan-shaped crystalline groups or
tufts, form also a beautiful and interesting gem stone.
Among
other inclusions, some of which might be utilized for gems, the
following may be mentioned from North Carolina: Quartz, including
scales of hematite from King's Mills, Iredell County; quartz containing
crystals of green spodumene (hiddenite) from Stony Point; inclusions of
|
|||
|
|
|||