The Greenlaws mine complex is located approximately one kilometer south of St. John's Chapel at Daddry Shield. Two parallel
veins, the Greenlaws East and West, were accessed by the mine, but the East Vein appears to have been far more productive.
The first work in the area appears to have been some medieval-period hushing on the West Vein. The Greenlaws East vein was
worked by the Beaumont Company between 1850 and 1884 for lead, and for a short period around 1860 it ranked as one of the major
lead-producing mines in Weardale. After the 1882 lead market crash the Beaumont Company gave up the mine, along with its other
holdings in the area. The lease was picked up by the Weardale Lead Company in 1884, and low-level work was done until 1897.
The workings ultimately accessed levels from the Little Limestone down to the Tynebottom Limestone from at least three portals.
Attempts to reopen the mine in the 1940s for fluorspar were reportedly unsuccessful, and with the exception of some recent
small-scale specimen recovery the mine has been idle since that time.
|A stone arched portal at the Middle Level of the
Dunham (1990) reports the presence of a small belt of cavity-bearing flats adjacent to the Greenlaws East vein at the High
Flats horizon in the Great Limestone, along with some in the upper portions of the Scar Limestone. Specimens of purple and
rarely amber fluorite have come from the mine and are still occasionally encountered in older collections. During the early
2000s a group of collector/dealers recovered some well formed, dark purple and occasionally amber- colored specimens of
untwinned fluorite from these flats. Access was gained by roping down an old shaft, but a change in property ownership put
an end to the project in 2006. More recently, another group of collectors has rehabilitated a shaft higher up on the moors
and gained access to a section of flats at the High Flats Horizon of the Great Limestone. Despite continuing logistical problems,
a limited number of specimens have shown up at British and Continental mineral shows over the past few years.
of yellow and purple fluorite crystals, up to 4 cm, overgrowing a mound of smaller purple fluorites,
from the Greenlaws Mine, East Vein. Specimen dates to the latter 19th century and was formerly in the
collection of Professor Harry Harwood, Manchester University.
West Pasture Mine
The West Pasture mine accesses the West Pastures vein, which is located on the eastern side of Stanhopeburn, approximately
2 kilometers north of Stanhope. Details of the history of the mine are scarce, but it is located near the Stanhopeburn mine,
which worked the eastern end of the Red vein first for lead, then fluorspar until the late 1970s. Dunham (1990) describes the
West Pastures vein as an eastern branch of the Red vein, and work on the West Pastures may have been related to activity at the
Stanhopeburn mine. He states that the West Pastures vein has been worked eastward from Stanhopeburn for 1,850 feet (564 meters)
in the Great Limestone, where flats of a limited extent have yielded a small quantity of lead ore. Unfortunately, no further
details are given.
untwinned fluorite crystals, up to 2 cm across, on a crust of galena and limonite from the West
Green and Briscoe (2002) reported that the mine was briefly reopened in the 1970s by the property owners to recover large
“decorator” specimens for their homes. When first recovered, West Pasture fluorite is often an attractive apple-green color.
Unfortunately, this quickly fades to an unattractive shade of purplish-gray with exposure to sunlight, and only specimens stored
in cabinets are likely to have retained their original color. Though in poor condition, the mine was accessible until just recently,
and was a popular destination for local collectors, who have recovered numerous specimens of fluorite from flats in the Great
Limestone in recent years. Crystals are usually untwinned and often occur on a galena and/or sphalerite crust.
White's Level, Middlehope
During the early to mid 19th century several lead mines were active along Middlehopeburn (“burn” is a local term
for a stream valley), to the north of the village of Westgate. In 1818 one of these mines – the Middlehope Shield
Mine, accessed by White’s Level – was the site of possibly the earliest major specimen find to be recorded in the
region. In the “Annals of Philosophy”, vol. XIV, published in 1819 is a short paper by Edward Daniel Clarke,
(then Professor of Mineralogy at Cambridge University) entitled “Account of a newly discovered variety of green
fluor spar, of uncommon beauty, with remarkable properties of colour and phosphorescence.” In this paper, he
describes a large find of “perfectly transparent, intense emerald green” fluorite that occurred at the Middlehope
Shield mine, near Westgate, in the autumn of 1818. He goes on to give a description of the specimens, noting the
crystal twinning, beveled edges, surface “laminae”, and buff-colored, often friable matrix.
|The portal to White's Level, Middlehope, in 2003.
Though active during the lead mining period in the 19th century, the Middlehope mines were not reworked for fluorspar
during the 20th century, and most are now protected archeological sites.
Specimens matching Clark’s description can be found to this day in many major museum collections, and occasionally
for sale in the mineral marketplace. Unfortunately, most of these specimens have been mislocated and are commonly
attributed to the nearby and better known Heights Mine. While both mines (as well as the Eastgate Cement Quarry and
the Rogerley Mine) are known for green fluorite, the characteristics described by Clark set these specimens apart
from those of the others. In particular, the matrix composition is distinctive in that most specimens from the Heights,
Cement Quarry and Rogerley occur on a dense, dark brown ironstone or a hard, silica replaced limestone rather than the
buff-colored friable material typical of White’s Level. In addition, the green color of many White’s Level specimens
has faded because of their exposure to daylight over a long period of time (Fisher, 2005).
|Twinned green fluorite crystals to 2 cm
across, on a tan-colored sandy matrix from White's Level. Specimen was formerly in the Philadelphia Academy
of Science collection.
Burtree Pasture Mine
Located in upper Weardale, just north of the village of Cowshill, The Burtree Pastures Mine was perhaps the single richest
lead mine in the region. Mining on the site is believed to date back to the 15th century (Fairburn, 1996), but development
of the present mine began after the property was acquired by the Beaumont Company around 1815. Between 1818-1883 extensive
underground workings were developed following the Burtree Pasture vein, penetrating into the Whinn Sill and northeast toward
Rookhope for a distance of almost 3 km. Dunham (1990) cites a production of almost 150,000 tons of lead concentrates from the
mine during this time period. With the collapse of the lead market, the Beaumont Company ceased operation in 1883, though mining
was continued at the site until 1890 by the Weardale Lead Company.
|The Burtree Pasture Mine near Cowshill, upper Weardale.
Photo likely dates from the late 19th century.
The mine was reopened in 1970 by Weardale Minerals (now owned by ICI) for fluorspar, appreciable amounts of which were believed
to have been left in place during the previous lead mining operations. Unfortunately, attempts to reach the lower levels in the
mine by rehabilitating the main shaft were not completely successful, and in 1977 the operation was acquired by Swiss Aluminium
UK (SAMUK). Instead of trying to reach the lower workings, SAMUK drove a new decline from the near-surface Horse Level into the
Great Limestone in an attempt to recover fluorspar remaining in the upper workings. Dunham (1990) reports that 47,200 tons of
crude ore was produced, but evidently the fluorspar content was fairly low and the project was abandoned as uneconomical in 1981.
|Main portal of the Burtree Pasture Mine during the SAMUK
period in the 1970s.
Despite the prodigious output of the mine, particularly during the lead mining phase, specimens identified as coming from the
Burtree Pastures Mine are relatively scarce. Dunham (1990) notes the existence of a small section of flats at the High Flats
horizon of the Great limestone, which contained purple fluorite, quartz, iron carbonates and calcite. It is likely that most
specimens known from the mine came from these flats during the SAMUK period of operation.
|A cluster of purple fluorite crystals with minor siderite and
quartz from the Burtree Pasture Mine. 14 cm across, recovered around 1974.
Several mineralized veins converge in the area around the Burtree Pasture Mine, and numerous mines, hushes and surface
workings have turned up much of the area over the past several centuries. Heading eastward toward Middlehope is the Sedling vein,
on which the Sedling Mine is located. Fairburn (1996) cites records of mining on the site as early as 1720, but like many other
lead mines in the area it was acquired by the Beaumont Company in the early 19th century, and operated by them until around 1878.
The mine was then taken up by the Weardale Lead Company, working it first for lead and then fluorspar until closure in 1948.
Exploratory drilling was done on the vein by both SAMUK and Weardale Lead during the late 1960s and early 1970s, but it appears
that the results were not encouraging as no further development was undertaken by either company.
Dunham cites a total fluorspar production of 166,421 tons between 1900 – 1948, and states that the mine was the
principal fluorspar producer in the district during that time. Despite this, known specimens from the mine are scarce,
though examples exist in the Russell collection at the Natrual History Museum, London. Dunham (1990) makes no mention of
any flats associated with the Sedling vein, which may account for the paucity of specimens.
|Purple fluorite crystals, both twinned and untwinned, on quartz,
with minor galena, from the Sedling Mine. An old label from the Mineral Department of the British Museum indicates that the
specimen was collected by Sir Arthur Russell in 1924.