SUNSTONE[GEM]
Listing description
Sunstone is a plagioclase
feldspar,
which when viewed from certain directions exhibits a brilliant spangled appearance; this has led to its use as a gemstone.
It has been found in Southern Norway, and in some United States localities. It
is the official gemstone of Oregon
Detailed description
Sunstone is a plagioclase feldspar, which when viewed from certain
directions exhibits a brilliant spangled appearance; this has led to its use as a gemstone. It has been found in Southern
Norway, and in some United States localities. It is the official gemstone of
Oregon.
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Properties
The optical
effect appears to be due to reflections from enclosures of red haematite, in the form of minute scales, which
are hexagonal, rhombic or irregular in shape, and are
disposed parallel to the principal cleavage-plane. These enclosures give the stone an
appearance something like that of aventurine, whence sunstone is known also as
"aventurine-feldspar." The optical effect called shiller and the
color in Oregon Sunstone is due to copper. In the middle part of this crystal,
it sparks a lot, and usually has a dark color in the middle, and the color
becomes lighter as it becomes the outer part.
The feldspar
which usually displays the aventurine appearance is oligoclase, though the effect is sometimes seen
in orthoclase: hence two kinds of sunstone are
distinguished as "oligoclase sunstone" and "orthoclase sunstone."
Distribution
Sunstone was not
common until recently. Previously the best-known locality being Tvedestrand, near Arendal, in south Norway, where masses of the sunstone occur embedded
in a vein of quartz running through gneiss. Due to the discovery of large deposits in
Oregon, Sunstone is now readily available.
Other locations
include near Lake Baikal in Siberia, and several United States
localities—notably at Middletown Township, Delaware County,
Pennsylvania,
Lakeview,
Oregon, and Statesville,
North Carolina.
The
"orthoclase sunstone" variant has been found near Crown
Point and at several
other localities in New York, as also at Glen Riddle in Delaware
County, Pennsylvania,
and at Amelia
Courthouse,
Amelia
County, Virginia.
Oregon sunstone
A variety known
as Oregon sunstone is found in Harney
County, Oregon
and in eastern Lake
County north of Plush. Only Oregon sunstone contains
inclusions of copper crystals.[2] Oregon sunstone can be found as large
as three inches across. The copper leads to varying color within some stones,
where turning one stone will result in multiple colors. The more copper within
the stone, the darker the complexion.[3]
On August 4,
1987, Oregon
State Legislature
designated Oregon sunstone as its state gemstone by joint resolution.
One of the leading mining operations is the "Dust Devil Mine", founded by rockhounds and which started selling Oregon sunstone in 1996. Many award winning gem cutters and carvers dig their own sunstone at the mine before cutting and carving them. Stones of over 300 cts have come from the pit.[6] The largest producing Oregon Sunstone mine is the Ponderosa Mine north of Burns, Oregon.
One of the leading mining operations is the "Dust Devil Mine", founded by rockhounds and which started selling Oregon sunstone in 1996. Many award winning gem cutters and carvers dig their own sunstone at the mine before cutting and carving them. Stones of over 300 cts have come from the pit.[6] The largest producing Oregon Sunstone mine is the Ponderosa Mine north of Burns, Oregon.
PRICE
$5518549.95/KG OR $2508431.79/IB
For more information:
mobile: +2348039721941
contact person: emeaba uche
e-mail: emeabau@yahoo.com
website: www.franchiseminerals.com

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