New British Update 21 September 2021

21 September 2021

HAVING recently visited so many worldwide locations in our updates, this week we return to home territory to offer an interesting selection of minerals from Britain.

Amongst today’s 21 specimens we have three from Wales, a smattering from Cumbria and Weardale, but principally from Cornwall. Cornish minerals seem to have universal appeal as they appear as popular with international collectors as much as those in the UK. The adjacent county of Devon is usually included with Cornwall as geologically they both overlie the Cornubian batholith, the large granite mass intruded around 280 million years ago and from which the abundant mineralization in these two counties derives.

Although the batholith extends west of the Cornish mainland under the Atlantic and to the east of Devon, the full extent of its manifestation at surface lies between the Isles of Scilly to the west and Dartmoor to the east. The main plutons which form the emanative centres of mineralization (and all exposed at surface) are, from east to west, Dartmoor, Bodmin Moor, St. Austell, Carnmenellis, Tregonning-Godolphin, Lands End and the Isles of Scilly. Minor granitic satellite bosses which branch from the plutons include localities we frequently encounter in our updates, St. Agnes, Carn Brea, Carn Marth, Cligga, Kit Hill and Hingston Down, for example.

Following this introduction, we had better then begin in Cornwall. From one of the more rarely encountered mines, Crenver and Wheal Abraham at Crowan, we have an unusual and well crystallised small cabinet specimen in which Chalcocite forms broad stacks of sooty black pseudo-cubic crystals. This specimen comes with a photocopy of what appears to be an Arthur Russell label which records this specimen is from the George Croker Fox (1727-1781) Collection.

From Carharrack, south of St. Day and to the east of Redruth, take a look at the large and heavy cabinet specimen of Native Copper; a specimen acid etched from a solid matrix. A 7 x 4 cm branch of almost pure Copper projects 4 to 5 cm from one side and when flicked with a finger, the entire specimen rings through with ‘metallic’ vibrations. The Copper is not crystallised, forming as sharp hackly fronds and branches.

From Wheal Druid, located on the lower northern flank of Carn Brea close to Pool, between Camborne and Redruth, dark metallic mahogany-red Cuprite crystals up to 3 mm richly cover a matrix of massive Cuprite. This fine small cabinet specimen comes with a Ward’s Natural Science Establishment of Rochester, N.Y. label. Francolite is the varietal name of carbonate-rich Fluorapatite and this cabinet specimen from Levant mine, close to St Just, is a beauty. A massive Quartz matrix coated with dark olive-green chlorite is overgrown by an almost continuous layer of 2 to 3 mm, clove to toffee brown Carbonate-rich Fluorapatite crystals with a bright glassy lustre and producing a sparkling surface.

Staying in the far southern tip of Cornwall, we have a charming large thumbnail of lustrous black Cassiterite crystals with micro-crystals of brassy golden Chalcopyrite from St. Michael’s Mount at Marazion, east of Penzance. If you are unfamiliar with St. Michael’s Mount, look it up on the web. It is a small picturesque island located in Mount’s Bay but connected to the mainland by a small man-made causeway. Passage is only possible at low tide, so the Mount does actually become an island twice-a-day. Although Chalcopyrite is known to occur here, specimens are very scarce. Collecting on St. Michael’s Mount has always been strictly forbidden because the mineral veins are exposed only on the privately owned side of the island, therefore the only specimens are those which have been collected historically.

Let’s move over to Wales now and without doubt, these are three Welsh classics: a Millerite from the International Colliery at Blaengarw near Bridgend; a Brookite from Twll Maen Grisial and a Brookite with Anatase, also from the Prenteg area of Gwynedd. The Millerite forms fine golden hair-like acicular crystals to 1.5 cm spanning a Siderite-lined cavity in a clay-ironstone matrix and was once in the Richard W. Barstow Collection, now accompanied with his white label. Twll Maen Grisial, a little to the southwest of Prenteg, is the type locality of Brookite and in this miniature over 20 semi-transparent golden bronze Brookite crystals of up to about 1 mm occur on Albite. The Brookite with Anatase is from the Prenteg area and displays a tabular Brookite crystal, 6 mm long, surrounded by several bluish black Anatase bipyramidal crystals to 1 mm embedded in the matrix.

From other regions do look at the bright lime green Pyromorphite from the Caldbeck Fells; a rich cluster of Scheelite crystals with Wolframite from Carrock mine and a delightful interpenetrant Fluorite twin from the world-renowned Hilton mine in Scordale. The honey-amber crystals range from translucent to reasonably transparent and are of the distorted cubic habit, up to 3.2 cm on edge.

We often say, for its relatively small size the British Isles contains a disproportionate wealth and diversity of minerals. Take Cornwall alone, mindat records 769 species from across 1,886 localities, quite remarkable for one of Britain’s smaller counties. There are many fine and interesting specimens in today’s update not mentioned above and they are well worth checking out. Be you a dedicated British mineral aficionado or just have a curious interest, we hope you enjoy today’s selection and possibly find something of interest. Enjoy. PT

                                         

If you'd like to see a video of any of the specimens listed above then please contact us at orders@crystalclassics.co.uk and we'll be happy to assist you. We endeavour to respond to all enquires within 24 hours during weekdays, however at the weekend it might take us a little longer to respond.

 

DATES FOR YOUR DIARY

Crystal Classics, and our sister company UK Mining Ventures, will be in attendance at the following shows for the remainder of 2021:

OCTOBER 9-10
The Bakewell Rock Exchange 2021
Lady Manners School, Bakewell, Derbyshire DE45 1JA, UK

OCTOBER 22-24
The Munich Show 2021
Exhibition Center Messe München, WEST Entrance, Munich, Germany

NOVEMBER 20
The Sussex Mineral & Fossil Show 2021
Haywards Heath College, Harlands Road, Haywards Heath, West Sussex RH16 1LT, UK

NOVEMBER 27
Crystal Classics Winter Open Day 2021
No.1, The Old Coach Yard, East Coker, Somerset BA22 9HY, UK

 

FOLLOW US ON SOCIAL MEDIA

If you don't follow us already, then make sure you check out our Social Media pages. Links to our Instagram and Facebook pages can be found via the icons below.

     

MINERAL WISH LIST

We also offer an additional service that enables you, as our customer, to contact us via orders@crystalclassics.co.uk with your mineral wish list to enhance your current collection, but are unable to find the right specimens on our website. We have 1000's of specimens in our general stock that do not appear online.

Author: JH
Categories: Updates

News Categories

News Archive