289

N e w occurrences of vanadium minerals (mottramite,descloizite, and vanadinite) in the Caldbeck areaof Cumberland.
By ART~VR W. G. KINGSBURu F.G.S.,
Dept. of Geology and Mineralogy, University Museum, Oxford,and J. HARTLnY, B.Sc., F.G.S.,
Dept. of Geology, University of Leeds.
[Taken as read 10 June 1954.]

Summary.--Four new occurrences of vanadium minerals are described. New
X-ray powder data are given for descloizite and mottramite, and show appreciable
differences. Evidence is brought that the original occurrence of mottramite was notat Mottram St. Andrew, Cheshire, but Pim Hill, Shropshire, and that most if not
all specimens labelled Mottram St. Andrew or Cheshire really came from Pim Hill.
ANADIUM minerals are rare in the British Isles, and only twospecies, mottramite (Cu, Zn)PbV0tOH and vanadinite Pbs(VO4)aC1,
have so far been recorded from a limited number of localities. We do
not include the vanadiferous nodules from Budleigh Salterton in Devon,as the vanadiferous mineral has not been identified. Mottramite,
supposedly from Mottram St. Andrew in Cheshire, was first described in
1876,1 b u t we have evidence (below, p. 293) that the locality was in fact
Pim Hill in Shropshire. ~ Vanadinite has so far only been found at
Leadhills and Wanlockhead in Scotland. Vauquelinite has been described from Leadhills and Wanlockhead,a b u t the specimens have since
been shown to be mottramite. 4
As a result of our investigations in the Lake District, we have foundseveral new localities in the Caldbeck area for raottramite, deseloizite,and vanadinite.
Higher part of Brandy Gill, CarroekFell. Mottramite, descloizite, andvanadinite occur here under varying conditions. About three-quartersof the way up Brandy Gill two old trial cross-cuts (now collapsed) havebeen driven, one on each side of the gill, on an east-west copper-lead

V

1 H. E. Roscoe, Proc. Roy. Soc., 1876, vol. 25, p. 111.
This locality is mentioned by F. A. Bannister, Min. Mag., 1933, vol. 23, p. 376.
a T. Davies, Min. Mag., 1877, vol. 1, p. 112.
4 F. A. Bannister, loc. cit., p. 377.

290

A.w.G. KINGSBURuAND J. HARTLEYON

vein. 1 We found a small specimen, showing minute yellowish-green
globular aggregates that proved to be mottramite, on the dump derived
from the upper western cross-cut. Shortly after this we located theoutcrop of the vein, and by blasting some of this out collected a considerable number of small specimens of mottramite. The primary sulphide minerals in this part of the vein are galena, chalcopyrite, andarsenopyrite; blende seems to be absent. A large amount of massive
greyish-brown mimetite is present in certain parts of the vein at theoutcrop and it is in cavities in this mimetite that most of the mottramite
occurs, forming yellowish-green to dark olive-green crystalline patches
and aggregates ; other associated minerals are bayldonite, malachite, andyellow mimetite. In other parts of the vein, cavities in quartz containwell-formed but minute olive-green crystals of mottramite ; the faces ofthese crystals, though bright, are rather rounded and striated and it has
not been possible to find one suitable for measurement; under the
microscope, however, they are seen to be pyramidal in habit and almost
certainly of the form o{111}, and while most of them show only this form
some appear to have small faces of M{011} and l{021} as well. The otherminerals associated with these crystals are bayldonite (in which they aresometimes implanted), beaverite, and beudautite. Mottramite, similar
to some specimens from Pim Hill, has been found in other material fromthis vein, forming dark brown drusy botryoidal aggregates with afibrous structure and giving a yellow streak.
On the dump from the eastern cross-cut on the same vein, descloizite,
a little mottramite, and vanadinite have been found in a spongy quartz
matrix which has very different characteristics from the vein-stuff on
the western side; copper minerals are uncommon, but small amountsof blende are present. Both the descloizite and the mottramite form
aggregates of small greenish-brown, brown, or reddish-brown crystals ;mottramite is by far the rarer. Vanadinite sometimes accompanies
mottramite or descloizite or occurs alone, forming short prismatic orbarrel-shaped crystals or globular aggregates, and ranging from palebuff to reddish-brown ; the lighter-coloured crystals are indistinguishable
in hand-specimens from mimetite, which is common at this locality.
The country-rock is granophyre, which has been much altered near thevein.
Grainsgill, near the foot of Brandy Gill. Vanadinite has been found1 A third cross-cut farther down the gill contains nothing of mineralogicalinterest. It is desirable to distinguish between the three cross-cuts, which are close
together.

V A N A D I U M I~IINERALS I N C U M B E R L A N D291

here in material from an old cross-cut driven close to the point where an
east-west copper-lead vein meets an ankerite vein and the Emersonvein, which here lie alongside each other; material from all three veinslies on a small dump, and much of it is iron-stained and gossany. SmallFIG. 1. Powder photographs of mottr~mite, deseloizite, and vanadinite. Camera
diameter 9 era. ; Cu-Ka radiation. 1.3~ottr~mite: llabelled] Mottram St. Andrew,Cheshire. 2. Mottramite: higher Brandy Gill, Caldbeck Fells, Cumberland. 3. Deseloizite: Venus mine, Sierra de C6rdoba, Argentina. 4. Deseloizite: higher ]~r~ndyGilt, Caldbeck FelLs. 5. Vaaadinite: MeDonal mine, Globe, Arizona, U.S.A. 6. Van~dinite: higher Brandy Gill, Caldbeck Fells.
amounts of vanadinite occur as small stout hexagonal prisms with basal
planes, ranging from pale buff to whitish and almost colourless ; the twolatter colours are most unusual in this mineral. Some of the crystals
show a central zone of banding, parallel to the basal plane, of a darker
and more brownish colour, a feature present in some very similar pyromorphite crystals from Roughtongill mine, Catdbeek. An interesting
feature of the vanadinite froln Grainsgill is t h a t it is slightly arsenical.

292

•.

w . G. K I N G S B U R u A N D J . H A R T L E Y ON

The country-rock here is greisen, but it is close to the gabbro of theCarrock Fell complex.
Potts Gill barytes mine, Caldbeek. Lead minerals are not of frequent
occurrence in this mine, but are present in some parts of the old workingsin small veins and strings away from the main baryte veins. Vanadinitehas been found here, in material on the dumps from the old No. 1 crosscut, as small brown prismatic crystals in cavities in cellular quartz, withbaryte and calcite ; these crystals, again, are practically indistinguishable
in hand specimens from similar crystals of pyromorphite from theRoughtongill area. The country-rock is Borrowdale Volcanic Series.
Netherrow Brow, Caldbeck. Mottramite occurs in small amounts inoxidized material from an unusual vein which carries large amountsof finely disseminated arsenopyrite, with galena, blende, pyrite, andtraces of chalcopyrite; this vein strikes approximately north-westsouth-east across l~etherrow Brow, on the northern slopes of theCaldbeek Fells north of Potts Gill mine. An old, grassed-over, collapsed
level near the farm of Netherrow has a small dump outside its entrance
containing a large number of secondary copper, lead, iron, and arsenic
minerals, and also a little olive-green mottramite forming small, drusy
botryoidal crusts on compact masses of earthy brown beudantite, closely
associated with beaverite and a little cerussite: the country-rock is again
Borrowdale Volcanic Series.
These occurrences make further interesting additions to the mineralsof the Lake District, but the source of the vanadium is a matter forconieeture. It is conceivable that some of the primary sulphides in theveins may have contained small amounts of the element, or that verysmall quantities of some other vanadiferous sulphide may have beenpresent. The vanadium in vanadinite has been generally considered
to be derived from vanadium-bearing sulphides or silicates in the gangue
or wall-rock: we do not know which of these possibilities is correct, but
it is to be noted that though in two instances the wall-rock is similar,
it is different at both the other localities.

The distinction between descloizite and mottramite by X-ray powderphotographs
During the growth of the library of X-ray photographs, in recentyears, at the Department of Geology in the University of Leeds, it wasnoticed that descloizite and mottramite gave different, though similar,
powder patterns. The photographs were all taken on cameras of 9 cm.

VAlgADIUMMINERALS IN CUMBERLAND

293

diameter, and since F. A. Bannister I considered t h a t the patterns of thetwo minerals were identical we decided to investigate the m a t t e rfurther. The discovery of m o t t r a m i t e at B r a n d y Gill provided an
additional reason for this investigation, and photographs of material
from other collections and localities have all confirmed the differences inpattern. Dr. Bannister kindly examined m a n y of these films, and after
re-examining his own films (taken on cameras of 6 cm. diameter) statedin a letter to H a r t l e y t h a t the differences were apparent on his films.
Films t a k e n recently at Leeds on a camera of 19 era. diameter haveemphasized the differences.
There appears to be no reason to differ from Bannister's original
conclusion t h a t descloizite and m o t t r a m i t e are the respective zinc andcopper end-members of a series, b u t no mineral so far examined has given
an intermediate pattern. Measurements of powder photographs of thetwo minerals show close agreement down to 1.652 *., b u t the smaller
spacings differ markedly. I n view of these differences in p a t t e r n it
seems advisable to give new powder data obtained from recent photographs, and these are set out in table I. Powder photographs of mottramite, descloizite, and vanadinite from some of the new Lake District
localities are given in fig. 1, together with photographs of correspo~dingmaterial from other localities.
A note on the origin ofmottramitefrom Mottram St. Andrew [A. W. G. K.]

As we have already mentioned (p. 289), there is good reason to supposet h a t the original occurrence of mottramite was at P i m Hill and not
M o t t r a m St. Andrew ; the evidence for this is partly historical and p a r t l ybased on the nature of the specimens. Although Roscoe obtained his
original material from Mottram St. Andrew, from piles of ore awaiting
treatment, the ore was p r o b a b l y not mined there. Most specimens ofm o t t r a m i t e in collections are labelled ' M o t t r a m St. Andrew', or simply' Cheshire', b u t there is no record of its being found in situ ; ' vanadiumore' has been reported from Alderley Edge.
Roscoe, 2 in his original description of mottramite, says t h a t it ' occurs
as a crystalline incrustation on Keuper sandstone found a t Alderley
Edge and at Mottram St. Andrew in Cheshire, and at other places', b u tthese localities clearly refer only to the Keuper sandstone. Vanadium
certainly occurred at Alderley Edge, and Roscoe s states t h a t he obtained
a supply of vanadium from a precipitate which was a by-product of the1 Loc. cir., p. 378.
~ Loc. cir., p. 111.
s H. E. Roscoe, Phil. Trans. Roy. Soe., 1868, vol. 158, p. 4.

294

A.W.G.

KINGSBURY AN]:) J'. I t A R T L E Y ON

TaBL~ I . X - r a y d a t a for descloizite a n d m o t t r a m i t e in J~. ; 9 c m . c a m e r a , C u - K ar a d i a t i o n ; b r o a d lines a r e a s t e r i s k e d : descloizite, F. 11401: V e n u s Mine, S i e r r a d eC6rdoba, A r g e n t i n a ; m o t t r a m i t e , P. 15661: M o t t r a m St. A n d r e w (B.M. s p e c i m e n ) .
Descloizite.

Mottramite. u

Descloizite.

Mottramite. ~I.

d (obs.).

I.

d (obs.).

I.

I.

d (obs.).

vs
msmm
mw
vvs
m

5"12 ~ .
4.75
4-25
4.00
3"54
3"34
3-23
3-04

vs
vs*

2-90
2"69
2.62
2-55
2.44

5"07/i~.
4-66
4.24
3-99
3.54
3'31
3.24
3'03
3.02
2-87
2.68
2-66
2.59
2.54
2-47
2.41v v w 2-37 ~ .
vvw
s
2.30s
m w 2.24
fmw
-~mw
s
2-10
fins~nls
m w 1.975mw
m w 1'898
w
m
1.866
mw
vvw
ms
1.787
ms*
m
1.757
vvw
w
vs
1-652
vs

2-39 -~.
2.30
2.24
2.22
2.10
2.08
1-967
1.912
1.871
1-837
1.782

vs*w
w

vsms
mm
mw
vvs
mvvw
vs
Svs
vs
vsw
vvw
vvw

\d (obs.).

1.721
1.657
1.648

T o this p o i n t t h e s p a c i n g s s h o w close a g r e e m e n t . S m a l l e r s p a c i n g s a r e different.
Descloizite.

Mottramitc. 2

Descloizite.

I.

d (obs.).

I.

d {obs.).

I.

d (obs.).

Mottramite. 2
I,d (obs.).

mms
mw
w
vw
vwv
s
vvw
vvw
mw
mw
w
vvw
vvw
w
wv
vw
mw
w
vvw
vvw
m
vvw

1.604J~.
1"565
1.517
1.507
1.466
1"446
1"409
1-392
1"370
1'360
1"334
1-309
1.287
1-268
1"241
1.209
1-201
1"178
1.160
1.152
1"130
1-115
1-107

mvvwmmw
mw
w
w
w
vw
ms
vvw
vvw
msvw
vw
vw
vw
w
wv
mw
vvw
vw
vvw

1.615A.
1-552
1.544
1.497
1.483
1-454
1.409
1"391
1'370
1-336
1.306
1.286
1.251
1'205
1-200
1.184
1"165
1.148
1.135
1.117]'089
1.078
1.067

vvw
vvw
w
vvw
vvw
vvw
vwv
vvw
mw
vvw
vvw
mw
mw
vvw
vvw
w
vw
vw
vvw
w
w
w

1.095•.
1.080
1.068
1.048
1-034
1.022
1.009
0.982
0.971
0.955
0"944
0.931
0-921
0'913
0-9060.896
0.885
0-878
0-863
0.853
0.848
0-837

vwv
vvw
vw
vw
vw
vw
vvw
vvw
vvw
vvw
vvw
vvw
vvw
vw
vw
vw
vw

1.050A.
1.032
1.018
0.990
0-977
0.970
0.950
0.940
0.930
0.923
0"907
0.895
0.888
0-878
0.861
0-852
0.845

1 N u m b e r o f film in X - r a y F i l m L i b r a r y , D e p t . o f Geology, U n i v e r s i t y o f L e e d s .
I d e n t i c a l p a t t e r n a n d s p a c i n g s a r e g i v e n b y m o t t r a m i t e f r o m P i m Hill, Shropshire, collected b y A. W . G. K i n g s b u r y .

VANADIUMMINERALSIN CUMBERLAND

295

extraction of cobalt at Mottram St. Andrew (by the Alderley Edge
Copper Mining Co.) from 'cobalt-bed sandstone'; he refers to the succession of beds containing this sandstone as that described by Hull, 1which is the succession at Alderley Edge and not Mottram St. Andrew.
I n the same paper 2 Roscoe describes this sandstone, and states that it' possesses a light colour and contains 0.1 to 0.3 per cent. of the oxides ofcobalt, nickel and copper disseminated as small black, green and red
specks throughout the mass' and that the vanadium probably occurs asvanadinite; he goes on to say that the mine at Mottram St. Andrew
had by then (1867) stopped working, preventing him from getting
further supplies of the material from which the vanadium precipitate wasprepared, and so it seems unlikely that the specimens of mottramite heobtained in 1875-6 were mined there. Moreover, since most of the known
specimens of the mineral are on a matrix unlike that from Aiderley Edge
and Mottram St. Andrew (the ore-bearing beds are conglomerate at thelatter3), the historical evidence against either locality being the correct
one is fairly strong. The mine at Pim Hill was working for a short periodaround 1875, and the ore is known to have been transported elsewhere
for treatment; this constitutes the only positive historical evidence
for Pim tIill as the correct locality.
Both Sir Arthur Russell and I have collected mottramite in situ at
Pim Hill in the parish of Preston Gubbals some 6 miles north of Shrewsbury ; the matrix here is a compact fine-grained Keuper sandstone, lightcream when fresh and often with small reddish-yellow streaks, whichbounds a fault running along the crest of the hill. This sandstone isidentical with the matrix of nearly all the specimens reputed to comefrom Cheshire, and moreover the habits of the mottramite itself are thesame, being a botryoidal or drusy crystalline coating on the sandstone(as described by Roscoe), only rarely occurring in the sandstone and thennot as a cementing medium; in all cases where mottramite is present
other minerals are conspicuously absent.
I n most eases the similarity of the 'Cheshire' specimens with thosefrom Pim Hill would seem to put their origin beyond doubt. Thus, while
there is no direct evidence, the historical and other data strongly suggestthat the specimens reputed to come from Mottram St. Andrew andCheshire really come from Pim Hill. This view is also held by Sir ArthurRussell, who agrees with the substance of this note.
1 Mem. Geol. Surv.: E. Hull, Geology of Stockport, &c., 1866, p. 39; see also
R. Hunt, British Mining (London, 1884), p. 260.
Loc. cir., p. 5.
a This is confirmed by all accounts.