Sterling
Hill and Franklin Zinc Mines
from
wikipedia ..."The Sterling Hill Mine, now known as the
Sterling Hill Mine Tour & Museum of Fluorescence,
is a former iron and zinc mine in Ogdensburg, Sussex
County, New Jersey, United States. It was the last
working underground mine in New Jersey when it closed
in 1986, and it became a museum in 1989. Along with
the nearby Franklin Mine, it is known for its variety
of minerals, especially the fluorescent varieties. It
was added to the National Register of Historic Places
in 1991.
Mining
began at the site in the 1630s, when it was mistakenly
thought to be a copper deposit. George III of the
United Kingdom granted the property to William
Alexander, titled Lord Stirling. Stirling sold it to
Robert Ogden in 1765. It went through several owners
until the various mines were combined into the New
Jersey Zinc Company in 1897. The mine closed in 1986
due to a tax dispute with the town, which foreclosed
for back taxes in 1989 and auctioned the property to
Richard and Robert Hauck for $750,000. It opened as a
museum in August 1990.
Franklin Furnace, also known as the Franklin Mine, is
a famous mineral location for rare zinc,[1] iron,
manganese minerals in old mines in Franklin, New
Jersey, United States. This locale produced more
species of minerals (over 300) and more different
fluorescent minerals than any other location. The
mineral association (assemblage) from Franklin
includes willemite, zincite and franklinite.
During
the mid-to-late 19th century the furnace was the
center of a large iron making operation. Russian,
Chilean, British, Irish, Hungarian and Polish
immigrants came to Franklin to work in the mines, and
the population of Franklin swelled from 500 (in 1897)
to over 3,000 (in 1913).
The
Furnace mine which was adjacent to the actual furnace,
was a 120+ foot vertical shaft just under Franklin
Falls. Other rare minerals include esperite,
clinohedrite, hardystonite, and others. There are
scores of minerals found only here, such as
johnbaumite (an arsenous apatite), mcgovernite, etc.
Sterling Hill, a very similar zinc orebody, is located
a few miles away in Ogdensburg.
Geology
The ore bodies at the Sterling
Hill mine lie within a formation called the Reading
Prong massif; the ores are contained within the
Franklin Marble. This was deposited as limestone in a
Precambrian oceanic rift trough. It subsequently
underwent extensive metamorphosis during the Grenville
orogeny, approximately 1.15 billion years ago. Uplift
and erosion during the late Mesozoic and the Tertiary
exposed the ore bodies at the surface; the glaciers of
the Pleistocene strewed trains of ore-bearing boulders
for miles to the south, in places creating deposits
large enough to be worked profitably.
In
the area of the Franklin and Sterling Hill mines, 357
types of minerals are known to occur; these make up
approximately 10% of the minerals known to science.
Thirty-five of these minerals have not been found
anywhere else.[9] Ninety-one of the minerals
fluoresce. There are 35 miles (56 km) of tunnels in
the mine, going down to 2,065 feet (629 m) below the
surface on the main shaft and 2,675 feet (815 m) on
the lower shaft. As of 2017, other than the very top
level of the mine (<100 ft), the entire lower
section has been flooded due to underground water
table and hence no longer accessible. The mine remains
at 56 °F (13 °C) constantly.
Museum
The
tour spends about 30 minutes inside the Exhibit hall
which contains a wide variety of mining memorabilia,
mineralogical samples, fossils, and meteorites. It
then leads into the mine for a 1,300 feet (400 m) walk
on level ground through the underground mine. The walk
goes through a new 240 feet (73 m) section called the
Rainbow tunnel which they blasted in 1990 using 49
blasts and at a cost of $2 a foot. In the Rainbow
room, short wave UV lights are turned on to
demonstrate the entire tunnel and various samples
glowing with fluorescence. The mine is also home to
the Ellis Astronomical Observatory, the Thomas S.
Warren Museum of Fluorescence, and a collection of
mining equipment.
The museum periodically arranges public mineral
collecting sessions as well as more private and behind
the scene events for local geology clubs."
Franklin
Mine Mill Site (from mindat.org)
"This is not a mineral
occurrence locality. It is now the site of an
apartment complex for senior citizens built in 2007.
All material formerly on this dump has been
mechanically sieved and removed and put in a special
area at the Franklin Mineral Museum. This is an
excellent example of conservatory co-operation
between a construction company and the Franklin
Mineral Museum.
This
locality was a mineral dump near the end of Mill
Street and abutting the ore railroad tracks entering
theformer Palmer #2 Mill. The "Mill Site dump" was
known for many years previous to the apartment
building construction and supervised field trips were
permitted in the mid-1980s. During the construction of
the apartment building, the dump was sieved using a 5
x 5 cm grid shaker and all of the mineral specimens of
"usable" size were trucked to the Franklin Mineral
Museum property, where these minerals are now being
added to the collecting site where museum members and
visitors are receiving controlled access to the
minerals, thus ensuring that fresh minerals are
available to mineral collectors and by extension
adding to the long-term vitality of the Franklin
Mineral Museum's facilities.
The
historical lore of the Mill Site Dump is that the
final approach to the Palmer #2 Mill (built in 1898)
was over a trestle about 8-12 meters from the rails to
ground level. Allegedly, the trestle shifted and was
perceived as unstable and management ordered a rapid
dumping of rock to bring the fill level up to the
railroad tracks and thus avert a long term mill
shutdown. Lore further suggests that the ore picking
table in the Mill was reversed so that any rock in the
Mill was diverted back to the trestle supports.
Further shipments of blasted rock of all kinds, both
dump-grade and ore-grade, were taken from the Parker
Shaft and elsewhere to fill the entire depression up
to track level. The presence of margarosanite,
hardystonite, and other desirable species that have
been recovered from Mill Site rock supports the
folklore."