An Introductory
Guide to Collector Minerals of |
Cornwall
& Devon including
photographs of |
|
CORNWALL & DEVON Closure of the South Crofty Mine near Camborne in the late 1990s, brought Cornish mining to an end. As is so often the case, it was driven out by economics, rather than by ore exhaustion. Earlier,
Wheal Jane, near Truro, had produced excellent ludlamite
specimens (type
locality for the mineral) It was the tail-end of around 300 years of ore extraction and of collector-grade specimens from active mines exploiting the metalliferous mineralizations associated with the Cornish granitic batholith. The region retains
its proud, mining tradition: Camborne is the centre for
the School of Mines. Evidence of mining The best specimens have probably been mined - now in collections and museums around the world - or remain in the bowels of the earth, awaiting an unlikely extraction. But it's not all doom and gloom! The region has a vast amount of tailings and dumps and the prospect of tungsten mining at Hemerdon, near Plympton, as recently announced (2008) may give future collectors something to pick over... Many dumps are forgotten and/or overgrown, lost to the expansions of modern living or are all too often well-picked over by collectors. Nonetheless, they occasionally yield the rare, the interesting and/ or unusual - though perhaps not always in hand specimen size. Examples include
Penberthy Croft Mine, St. Hilary, Cornwall, which yielded
some excellent, bayldonite Recently, good specimens of scorodite, arsenopyrite, barite and allophane have been recovered from sites in Devon. The deposits of China-Clay also produce, on occasions, an interesting array of common and rare species. A major, primary export resource for the region and the UK, they are centred around St. Austell, with its unique and distinctive landscape created by the mining operations and the "reclaimed for Nature" landscaping projects. |
LIROCONITE
Chalcopyrite-coated
TETRAHEDRITE |
Tin & Much More... Cornwall and tin are synonymous and although cassiterite is an essential species in all Cornish collections, other common and very rare mineral species are also strongly represented. By merely mentioning a mineral species, Cornwall may regularly spring to mind. Several mines are noted for distinctive suites or assemblages of minerals. The famous copper arsenates, including liroconite, clinoclase, ceruleite, cornubite, cornwallite, as well as the associated species of scorodite, pharmacosiderite, cuprite and chenevixite from Wheal Gorland is one example. |
CASSITERITE |
PHOSGENITE - Padstow, Cornwall. |
LUDLAMITE - Wheal Jane, Kea, Truro,
Cornwall. |
CONNELLITE
& Malachite |
STRUNZITE |
Type Localities The region is the type locality for a fair number of minerals and many of these are regarded as rare mineral species. Such examples include liroconite, chalcophyllite, cuprite and bournonite. In Devon, the
native gold occurence Apart from the delicate specimens of gold it has produced, rare platinum and selenium minerals have also been recorded at the location. |
CHALCOCITE |
OLIVENITE |
ARSENOPYRITE - Bedford Consols, Tavistock, Devon. |
BARITE - Sidmouth, Devon. |
Classic Localities - Famous Specimens The mines and
mineral localities recorded in the region are almost
endless and several have passed into the annals And from
Cornwall, similar examples include the largest-known
liroconite crystal from Wheal Gorland |
The
geology of this part of the country lends itself more to
the fossil collector - |
PYRITE/
MARCASITE |
CELESTITE |
The
classic celestite deposit at Yate, near Bristol is one
notable mineral occurence. Also noteworthy is the
marcasite-crystal form pyrite found at
Climping Beach in Sussex. In Kent, typical sedimentary
occurences of Deserving special mention are the rare species found in the Mendip Hills in Somerset, such as diaboleite and mendipite. Mereheadite, parkinsonite and the more recently described new mineral species, symesite, also have their type locality in the area, at Merehead Quarry. The Mendip area also yields interesting specimens of some of the more common mineral species. Dulcote "picture stone" or polished agate is well-known and interesting specimens of goethite, quartz and calcite can also be found at the locality. |
QUARTZ - Dulcote Quarry, Wells, Somerset. |
the end
References / Further Reading (of the more recent and accessible literature)
Book
Minerals of
Cornwall & Devon. P.G. Embrey & R.F. Symes.
(British Museum Natural
History/ Mineralogical Record publication, 1987). Highly recommended!
Magazines/ Journals
Mineralogical
Record,
vol. 18, no.1 - Gold - Special Issue - 2. Hope's Nose, Torbay,
England. (1987)
vol. 24, no.4 - Cornwall's Famous Mines (P. Bancroft & S.
Weller). (1993)
vol. 27, no.4 - Famous Mineral Localities: The Higher Pitts Mine,
Mendip Hills, Somerset, England, (P.S. Burr). (1996)
UK Journal of Mines
& Minerals (UKJMM)
vol 14 - pp 21-33- The Minerals of the China Clay Pits, (S.
Weiss). (an updated English translation of a Lapis Magazine
article). (1994)
vol 18 - pp 17-32- The Royal Cornwall Museum, (R. Penhallurick).
(1997)
vol 19 - pp 18-23- Ting Tang Mine, (I. Bruce & D.
Aubrey-Jones). (1998)
vol 20 - pp 7-37- Famous Mineral Localities: Penberthy Croft
Mine, St. Hilary, Cornwall, England. (J. Betterton). (2000)
vol 23 - pp 27-35 - Barite & Supposed Celestine from the
Triassic Mudstone of Sidmouth, Devon. (K.D. Corrie & D. I.
Green) (2003).
© Minerals of Scotland - 2008.