An Introduction to the Minerals of |
Introduction - Alston Moor, Cumbria including photographs of |
An Introduction to the Minerals of |
Introduction - Alston Moor, Cumbria including photographs of |
SITE LINKS
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Introduction Alston Moor, in north-east Cumbria, on the northern edge of the Pennines, was formerly a major lead-zinc orefield during the 19th century. It has yielded fine, collector specimens of both common and rare mineral species from that period up to the present day, despite it no longer being active as an ore producer. Just a few miles farther east, in County Durham, is the famed Weardale fluorite region, renowned for its fluorite specimens with their typical and regularly twinned, cubic crystals. Like Alston Moor, ore was extracted in the past. In the case of the Weardale mines, fluorite and latterly barite were important ores.
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| Weardale, County Durham There are several classic localities in the Weardale district of great interest to collectors. The specimens of fluorite in particular which they produced adorn the finest mineral collections in the world. The most
famous mines that produced fluorite as specimens - Apart from the variety of colours, aesthetics and the often well-sized crystals from these and other localities in the area, Weardale fluorites have the additional attraction of their renowned, strong fluorescence - normally a brilliant lilac colour. Other than fluorite from these mines, perhaps of special note as collector specimens is pyrrhotite from Cambokeels Mine. Galena, sphalerite and calcite - often as good crystals - are also frequently associated with the fluorite of the Weardale mines. |
FLUORITE - Greenlaws Mine, St. John's Chapel, Weardale, Co. Durham. Deep purple crystals to c 27mms. (95x60mms). |
The Rogerley Mine Despite the closure of the Weardale mines, a new development of great interest to collectors, is the working of some of the mines on a commercial basis for specimens. The extraction of fine fluorite specimens is taking place at the Rogerley Mine - thanks to a recent commercial venture (see below) and also at the Greenlaws Mine. In the summer of 1999, an American consortium, UK Mining Ventures, (entrepreneurs in the commercial extraction of mineral specimens, specifically for the collector market), began operations at the Rogerley Mine. The consortium were in search of the mine's well-known, typical, rich green cubic fluorite crystals which, in the best examples, often display a strong, daylight fluorescence! Since then, numerous good specimens of both green and purple crystals have been extracted from several newly-discovered mineralized pockets. These results can now be seen at most major mineral shows and mining activities are ongoing. |
FLUORITE - Rogerley Mine,
Weardale. A detailed and graphic account of the specimen extraction so far, the background and the history of the mine can all be viewed by visiting www.ukminingventures.com The site also has a section for specimen purchases. |
Alston Moor, Cumbria This area lies predominantly in the county of Cumbria, but the orefield stretches into the edges of the neighbouring counties of Durham and Northumbria. The main centre of mining activity was around Nenthead where there are a number of mines: Smallcleugh, Capelcleugh, Scraith Holes, Nentberry Haggs, Settlingstones, Fallowfield and Brownley Hill being amongst the most well-known. Several of these mines have yielded excellent specimens of the more common species, such as galena, calcite and sphalerite. These minerals are synonymous with the area. However, the Alston Moor area is also the type locality for the minerals barytocalcite, witherite and alstonite: a fact which gives the mines of the area and their minerals a lasting significance. The type locality minerals are less common, but the area has yielded some of the best examples known for these species - and occasionally in recent finds made by collectors. Also in recent times, an increasing number of secondary species have been recorded by collectors. |
GALENA - Nentberry Haggs Mine, Nenthead, Alston Moor, Cumbria. Multiple-twinned crystals of galena to 1 cm.. |
BARYTOCALCITE - Nentberry Haggs Mine, Nenthead, Alston Moor, Cumbria. Curved, creamy crystals in aggregates to 15mms on calcite. |
WITHERITE (part
pseudomorph) - Nentberry Haggs Mine, Nenthead,
Alston Moor, Cumbria. |
SPHALERITE - Smallcleugh Mine, Nenthead, Alston Moor, Cumbria. Intergrown crystals to 15mms. |
ALSTONITE - Brownley Hill Mine, Nenthead, Alston Moor, Cumbria. Bi-terminated, hexagonal pyramids to 9 mms with galena. |
| ACKNOWLEDGEMENT: This
website would like to express its sincere thanks to Jesse
Fisher of UK Mining Ventures for the photograph of
Rogerley fluorite and for the earlier publication of a
synopsis on activities at the Rogerley Mine. References/ Further Reading BOOK
- Rocks
& Minerals UKJMM
(United Kingdom Journal of Mines & Minerals) Mineralogical
Record © Minerals of Scotland |
