124

MINERALOGICAL NOTES

and Kelly, 1964; Mann, 1984; Stoffregan, 1986)
that gold is mobile as a chloride complex. The
gold at Botallack may well represent an enrichment by such a process.

Andersonite and schr6ckingerite
from Geevor mine, Cornwall: twospecies new to Britain
SCHROCK1NGERITE,

Acknowledgements. To C. J. Stanley and R. S. Scrivener for information on the distribution of gold in southwest England, and to J. F. W. Bowles for reviewing thenote.
References

Andrew, R. L. (1980) Supergene alteration and gossan
textures of base-metal ores in Southern Africa.
Mineral Sci. Eng., 12, 193-215.
Bowell, R. J. (in press) Supergene copper mineral
assemblages at Botallack, Cornwall. J. Russell Soc.
Clark, A. M. and Criddle A. J. (1982) Palladiumminerals from Hope's Nose, Torquay, Devon.
Mineral. Mag., 46, 371-7.
Clayton, R. E., Scrivener, R. C., and Stanley, C. J.
(1990) Mineralogical and preliminary fluid inclusion
studies of lead-antimony mineralization in North
Cornwall. Proc. Ussher. Soc., 7,258-62.
Cloke, P. L. and Kelly, W. C. (1964) Solubility of gold
under inorganic supergene conditions. Econ. Geol.,59, 259-70.
Dewey, H. (1923) Copper ores of Cornwall and Devon.
Memoirs of the Geological Survey of Great Britain.
Mineral Resources I, London.
Dines, H. G. (1956) The metalliferous mining region ofSouth-West England. (2 vols) London (H.M.S.O.).
Mann, A. W. (1984) Mobility of gold and silver inlateritic weathering profiles: some observations from
Western Australia. Econ. Geol., 79, 38-49.
Russell, A. (1944) Notes on some minerals either rareor new to Britain. Mineral. Mag., 28, 1-10.
Stanley, C. J., Halls, C., Carom, G. S., and James, J.
(1990a) Gold-antimony mineralization Loddiswell,Devon, UK. Terra Nova, 2, 224-31.
- - C r i d d l e , A. J., and Lloyd, D. (1990b) Precious andbase-metal selenide mineralization at Hope's Nose,Torquay, Devon. Mineral. Mag., 54, 485-93.
Stoffregan, R. (1986) Some observations on the behaviour of gold during supergene oxidation at Summitville, Colorado, USA, and implications for electrum
stability in the weathering environment. Appl. Geochem., 1,549-58.
KEYWORDS:gold, Botallack mine, Cornwall.
R. J. BOWELL
Dept. of Geology, The University, Southampton
S09 5NH
Now at Dept. of Mineralogy, The Natural History
Museum, London SW75BD[Manuscript received 4 February 1991;
revised 4 March 1991]
9 Copyright the Mineralogical Society

NaCa3(UO2)(CO3) 3-(SO4)F.10H20, is the most abundant of theuranyl carbonates and is of relatively widespreadoccurrence. It was first found at Joachimsthal,
Czechoslovakia, as an alteration product ofuraninite (Schratlf, 1873). It is found at numerous
locations in the U.S.A., notably Wamsutter,
Wyoming, Yavapai County, Arizona and several
localities in Utah (Hurlbut, 1954; Frondel, 1958);
it has even been mined as the primary ore in a few
small deposits (Smith, 1984). Schr~3ckingerite has
also been reported from eastern Germany, Austria and Argentina (Frondel, 1958). In most of thedeposits the habit is similar, described as globular
aggregates of minute scales; distinct crystals toaround one millimetre have also been reported(Hurlbut, 1954).
Andersonite, Na2Ca(UO2)(COa)3.6H20, wasfirst described by Axelrod et al. (1951) fromspecimens collected at the Hillside Mine, YavapaiCounty, Arizona, where it occurred as clusters ofminute pseudo-cubic crystals, associated withgypsum, schr6ckingerite, bayleite and schwartzite. The mineral has subsequently been reported
from other localities in the U.S.A., notably
Grand County, New Mexico and San JuanCounty, Utah where it occurs as rhombohedral
crystals to around 12 mm (Frondel, 1958; Robertset aL, 1990).
Both andersonite and schr6ckingerite havenow been found at the Geevor mine, Pendeen,
Cornwall, where they occur on the walls of a drivealong the Peeth Lode on 17 Level (1700 feetbelow surface). This is the first recorded occurrence of these species in Britain.
Most of the schr6ckingerite and andersonite is
restricted to one part of the drive with a linear
extent of approximately 4 metres. In this area theschr6ckingerite occurs as small greenish-yellow
spheroidal globules, up to 4 m m in diameter,
widely scattered over the tunnel wall. Specimensof this material were first brought to the authors'attention by Mr E. Gale of Geevor Tin Mines plc.
Superficially, the (unbroken) globules appear
featureless, but closer examination reveals them
to be composed of aggregates of tiny, euhedral,
pseudo-hexagonal plates (typically around 50 ~macross, occasionally to 0.2ram). Some appear tobe cemented together by gypsum over the outersurface. This habit is similar to that recorded inother deposits (Hurlbut, 1954). The samples
exhibit a strong yellowish-green fluorescence,
which produces a remarkable display in situ on
the tunnel walls.

M I N E R A L O G I C A L NOTESThe andersonite is much less common. Itoccurs as small masses of intergrown, pseudocubic crystals to 3 mm on edge. The crystals aretransparent and of a bright yellow-green colour,and exhibit very bright yellow-green fluorescence
under long-wave UV light, similar in colour andintensity to that of the schr6ckingerite aggregates.
The walls of the drive are composed of granite
traversed by quartz veinstone carrying minor
sulphides. However, much of the tunnel wall iscoated with a friable, sandy material, cemented tothe underlying rock by gypsum, and the schr6ckingerite and andersonite are commonly found on
this substrate.
Identification of the schr6ckingerite wascarried out by X-ray powder diffractometery. TheXRD analysis showed the aggregates to becomposed of a mixture of gypsum and schrOckingerite. The andersonite was tentatively identified as such following examination by energydispersive X-ray analysis. Both schr6ckingeriteand andersonite were subsequently confirmed by
X-ray powder diffraction at the British Museum(Natural History) (film numbers 8567F and 8568F
respectively).
The andersonite and schr6ckingerite occur inclose association with each other at Geevor. In afew specimens, schr6ckingerite-gypsum aggregates are observed partially intergrown withandersonite. Other secondary uranium mineralisation occurs along the Peeth Lode. Yellow
zippeite-type secondaries are widespread along
the tunnel walls. Johannite is also found in thesame area and specimens in the possession of theBritish Museum (Natural History), collectedfrom this location in 1986/87, are associated with amineral tentatively identified as becquerelite(P. C. Tandy and J. G. Francis, pers. comm.).
However, these species are rarely seen in close
association
withtheandersoniteandschr6ckingerite.
Samples of the audersonite and schr6ckingerite
have been lodged with the British Museum(Natural History) and the University Museum,Oxford.
Acknowledgements. The authors wish to thank R. F.
Symes, P. C. Tandy and J. G. Francis of the British
Museum (Natural History) for useful discussions andthe X-ray powder photography. The authors are also
grateful to ECC International for the use of analytical
instrumentation.
References

Axelrod, J. M., Grimaldi, F. S., Milton, C., andMurata, K. J. (1951) Am. Mineral., 36, 1.

125

Frondel, C. (1958) USGS Bull., 1064, 115.
Hurlbut, C. S. (1954) Am. Mineral., 39, 901.
Roberts, W. L., Campbell, T. J., and Rapp, G. R. Jr.
(1990) Encyclopedia of Minerals, 2nd Edition (VanNostrand Reinhold, New York).
Schrauf, A. (1873) Min. Mitt. no II, 137 [Source:Hurlbut (1954)].
Smith, D. K. Jr. (1984) Uranium Mineralogy. In
Uranium Geochemistry, Mineralogy, Geology,
Exploration and Resources (De Vivo, B. et al., eds)
Institution of Mining and Metallurgy.
KEYWORDS: schr6ckingerite, andersonite, Geevor mine,Cornwall.
N. J. ELTON
Tregea~, Little
PL26 7QL.

Trev~coe,

St Austell,Cornwall

J.J. HooPER
48 St Julitta, Luxulyan, Bodmin, Cornwall PL30 5ED[Manuscript received 12 July 1991]
9 Copyright the Mineralogical Society

Mineral nomenclature: sulrhodite
THE crystal structure of synthetic Rh2S 3 wasdescribed by Parth6 et al. (1967) in spacegroupPbcn (60) with a 8.462, b 5.985, c 6.138 A and
Z = 4, to a R value of 0.069. The Rh atoms
occupy a single set of eight atomic positions.
Bowieite (Rh, Ir)2S3 described by Desboroughand Criddle (1984) has a 8.454, b 6.002 andc 6.121 A in space group Pbcn (60). Bowieite wassubmitted to the International Mineralogical
Association Commission on New Minerals andMineral Names (CNMMN) on 14 March, 1980.
The records show that it was approved (20-0 forthe mineral, 19-0-1 abstention for the name) inthe CNMMN memorandum dated 21 June, 1980.
The delay between approval and publicationoccasioned by a great deal of extra work on thecomposition and optics was sanctioned byCNMMN.
Sulrhodite Rh2S3 described by Keqiao et al.
(1983) has b 8.493, c 5.987 and a 6.167A in spacegroup Pnca (60) similar to PDF 21-1017. The
paper was received by Kexue Tangbao on July 29,1981; however, sulrhodite was never submitted tothe CNMMN.
The two minerals have an identical endmember formula of Rh2S3 and identical crystalstructure. Based upon the rule of priority, bowie-