CanadianMineralogist
Vol. 19,pp. 337-340(1981)
SPERTINIITE,Gu(OH)2, A NEW MINERAL FROM THE JEFFREY M|NE, OUEBEG
J.D. GRICE
NationalMuseuntol Natural Sciences,
Minerul SciencesDit'ision,Ottav'a,OntarioKIA 0M8
E. GASPARRINI
Minntet ScientificLinrited,P.O. Box 921, Toronto,OntarioM4P 2H2
Asstnlcr
Spertiniite, a new speciesfrom the Jeffrev mine.
Quebec, occurs as small botrvoidal aggreg0tesassociated with chalcocite, native copper and atacamite on a rodingite dyke. It forms blue to blueereen, lathlike crystals ( l0 pm in size. It is optically anisotropic. with parallel extinction and
positive elongation; pleochroism is strong, with X
colorless and Z dark blue; indices of refraction c
1.720(2), ? > 1.800(2). An electron-microprobe
analysis gave 66.9Vo Cu and O.lVo Cl. By analogy
with syntheticCu(OH)o (PDF 13-420), spertiniite
is orthorhombic, space group Ctncm, and Z = 4;
refined cell parametersarel.a 2.951(l'), b 10.592(3),
c 5.257Q\ A. fne srongest nine lines of the X-ray
powder-diffraction pattern are 5.28(80)(020).
3.73 (e0 ) (02'.t\, 2.632(I 00) (002), 2.494(60) ( | 11) .
2.362(sO)(041,022), 2.264(7OJir30), 1.929(30)
( l l 2 ) , 1 . 7 1 6 ( 7 0() 1 5 0 . 1 3 2 )a n d 1 . 4 3 8 ( 3 0()1 5 2 ) A .
The nreasured density is 3.93(2) g/cme and the
calculated density, 3.94 g,/cm'.
Keyworcls; spertiniite, new mineral. cupric hvdroxide. Jeffrey mine. Qu6bec. rodingite.
Sovuernr
La spertiniite. espBcenouvelle trouvde ir la mine
Jeffrey (Qu6bec), se pr6sente en petits asr6gats botryoidaux avec chalcocite. cuivre natif et
atacamite associ6s,dans un dyke de rodineite. Les
cristaux en lattes, de taille infErieure ir l0 um.
passent du bleu au bleu-vert. Optiquement ils sont
anisotropes,ii extinction paralldle. allongement positif et fort pl6ochroisme (X incolore. Z bleu fonc6); leurs indices de r6fraction sont o l.7ZO(2), t
> 1.800(2). IJne analyse i la microsonde 6lectronique donne 66.9Vo Ct et 0.1Vo Cl. Par analogie
avec le Cu(OH), synth6tique (PDF 13-420), la
spertiniite est orthorhombique, groupe spatial Cmcm,
t 2.951(r), h r0.s9z(3), c 5.257(3) A. Z - 4. Les
neuf raies les plus intenses du clich6 de poudre
en A. (t) (/r&/)l sont: 5.28(80)(020), 3.73196;
ld1,y1
(021). 2.632(100)(002\, 2.494(60)(rrr). 2.362
( s0) (04r.022). 2.264(70) (130\. 1.929i3'0) ( rr2 t,
1 . 7 1 6 ( 7 0()1 5 0 , 1 3 2 )e t 1 . 4 3 8 ( 3 0()l 5 2 ) . L a d e n s i t 6
mesurdeest de 3.93(2), calcul6e3.94.
(Traduit par la R6daction)
Mots-c'lds;
spertiniite,espbcemin6ralenouvelle,hydroxyde cuprique,mine Jeffrey. Ou6bec.rodineite.
INtRoouc].tol.t
During a study of the minerals from the
Jeffrey mine, Asbestos,ShiptonTownship, Richmond County, Quebec(Grice & Williams 1979),
a natural occurrence of Cu(OH)r was discovered.This specimenwas submittedfor identification to one of the authors (J.D.G.) by Mr.
F. Spertini, Chief Geologistat the Jeffrey mine,
Johns-ManvilleCanada Incorporated; it is with
great pleasure that we name this new mineral
speciesspertiniite.
The name and the mineral have been approved b), the Commissionon New Minerals and
Mineral Names, I.M.A. The holotype specimen
of spertiniite consistsof a few mg of material
on matrix measuring3x3x2 cm. This specimen
is preservedat the National Museum of Natural
Sciences,Ottawa (NMNS 44696) along with
cotype material (NMN^! 44697, 44698 and
44699).
OccunnrNce
Spertiniite is a very rare mineral, found in
a rodingite dyke exposedin the east side of the
Jeffrey mine open pit. At the time of discovery,
January 1978, the exp.osureof the dyke measured I m in thickness by 8 m in length (F.
Spertini, pers. comm. 1980). Spertiniite occurs
in the lower portion of the dyke near the contact with the host serpentinizeddunite. This
portion of the rodingite consists primarily of
fine grained,dense,white diopsideand grossular,
partly coated with pale green vesuvianite.Wares
& Martin ( 1980) gave further details of the
petrology of this assemblage.
Chalcocite commonly constitutes the core of
the botryoidal massesof spertiniite,which also
contain atagamite. Minor amounts of copper
337
338
THE
CANADIAN
are associatedwith spertiniite in the rodingite.
A second occurrence of spertiniite from Ely'
Nevada, has been reported by Miss E.E. Fejer
(pers. comm., 1980), British Museum (Natural
History), London ( 8M1972,193).
PHYSICAL aNu
OPrtcll-
PRoPERTIES
Spertiniite forms discrete botryoidal aggre-
MINERALOGIST
gaies approximately 100 g,m in diameter (Fig.
I ). SEM observation shows them to be composed of lathJike crystals, often having a
radial habit (Fig. 2), with their longest dimension approximately l0 pm' Spertiniite is blue to
blue-greenand transparent with a vitreous lustre'
It is soft and crusheseasily without any marked
cleavage. It does not fluoresce in ultraviolet
radiation. There was insufficient material for
Frc. l. Botryoidal aggregates of spertiniite on rodingite mafix'
image; width of field of view is 380 pm.
SEM
FIc, 2, Radial aggregatesof lath-like crystals of spertiniite. SEM image;
width of field of view is 230 pm.
sohrbility measurementson spertiniite, but Weast
(1977) reported that synthetic Cu(OH)r is insoluble in cold water, decomposesin hot water
and is soluble in acids.
Three grains were used in the density determination of spertiniite. Grains were suspended
in Clerici solution (thallous malonate/formatewater mixtures) at. 22"C, and densities of the
matching solution were measured in a 2-cm3
pycnometer. The measured density, 3.93(2)
g/cm3, compares well with the calculated density of Cu(OH)r, 3.94 g/cm", with Z:4 and
V:1643 43.
Optical measurementson spertiniite were difficult owing to the small crystal size. It is
optically anisotropicowith parallel extinction and
positive elongation. Pleochroism is strong, with
X colorless and Z dark blue. The indices of
refraction are a 1.72O(2) and 7 >1.800(2);
this phasereacts with immersion liquids having
r) 1.800.
lIM
I.
FRAY }CIIIRDITFMCTICtrI
@ruc mrcro
DAN TOR SPRTI,UTE
qPuc
PERTINITB
fuas
dcalc
<t_0
5.29
3.73
2.A4
100
60
2.63
2.50
50
z"ot
70
20
30
2.266
2.017
1.931
<f,0
70
L.764
1 'a
t0
r.670
20
t0
br.0
1.631
1.493
L.474
b10
30
1.461
1.440
5.29
3.73
2.84
2.65
2.63
2.50
2.365
2.3y
2.264
2.079
r.930
1.866
1.765
r.72J
1.716
r.673
J,.664
r.635
L.492
L.475
),.466
1.461
1.440
r.42r
1.386
L.372
1.346
I.324
1.3L4
1.304
r.289
1.287
L2A4
L.216
L.252
l-2il
L.228
L.198
1.193
1.182
!.I77
1.157
1.L37
l.l-32
.l€t
80
,
\
r'
1.373
<10
<r0
CnystetLocnlpHy
Spertiniite crystals are tabular (Fig. 2), but
neither morphological nor single-crystal X-ray
studies could be made owing to the microcrystalline natnre of the aggregates.Using powder
patterns generatedwith a 114.6 mm Gandolfi
camera, 38 diffraction lines were measured; of
these, 19 could be indexed and were suitable
for least-squares refinement. The indexing is
based on the orthorhombic cell and spacegroup
Cmcm determined by Jaggi & Oswald (1961)
for synthetic Cu(OH)r. The refined unit-cell
parameters and volume arc a 2.951U.), b
10.592(3), c 5.257(3) A and V 164.3Q) N.
The X-ray powder-diffraction data for spertiniite
and syntheticCu(OH)e (PDF l3-420) are given
in Table l.
339
MINE
SPERTINIITE FROM THE JEFFREY
1.301r.2e1
,
t
10
<10
L.?26
<10
1.181
l_0
L.136
r*
additi@l.
I
|
I
Eak
liN
020
02L
110
040
002
LLL
04r
o22
130
l3lJJ2
042
060
150
r32
061
023
r-5r
lt3
200
062
043
r52
220
133
22L
170
080
004
171
240
2O2
081
024
24I
222
L53
n2
Lt4
042
U4
242
L34
260
bel@,
ltrffiit-tes
AID SYNMMC
]mr
l@s
dmeas
90
L00
2
<1
70
5.30
3.73
!2
16
2
<1
6
35
2.63
2.50
2.364
2,263
2.O78
r.929
L.797
L.72
L.492
L.4'76
L.466
T2
4
6
L.439
L.420
1.385
L.372
L.346
!,324
1.3L4
1,304
1.285
L,275
6
L.249
2
<I
r-224
4
<<r
1.180
1.131
<10
l@a,
c!(u radi*io.
u4.6 @ Gtdol.fi
rJ@6 @d S13-420
,*r.039, .98r.
.9617, .947J", .930A. .9222, .9149, .9059, .4907, .464L,
.a442t .AI47, .1NO, .7743.
wavelength-dispersionspectrometry with 20 kV
accelerating voltage and 0.5 pA sample current
measured on spertiniite-atacamite. Standards
used were copper metal for copper and halite
for chlorine. The intensity counts emitted at
the copper and chlorine Ka wavelengthsby the
Cusl4rclr CoupostttoN
standards and minerals were reduced by the
All the chemical analyseswere performed on computer program EMPADR VII (Rucklidge &
an ARL-EMX electron microprobe with a solid- Gasparrini 1969).
state detector for analysis by energy dispersion.
A preliminary qualitative study of the spertiAlthough the microprobe is not normally the niite, in a predominantly diopside matrix,
best instrument for the study of hydrous min- showed that the mineral is very fine grained,
lV20 pm in size, and intimately associated
erals (neither O nor H is detected), it was in
our case the only one capable of analyzing with atacamite,from which it is not distinguished
grains as fine as those of spertiniite.
optically in polished section. The qualitative
The qualitative study was done by energy- study also showed that the mineral consists of
dispersion spectrometry and involved the col- copper with very minor chlorine and no other
lection of X-ray spectra showing peaks at the minor elements. Quantitative analyses of the
energy positions of the various elements above spertiniite and atacamite for copper and chlorine
atomic number 10 constituting the analyzed gave amounts of the two elementsvery close to
grains. The quantitative analyseswere done by the stoichiometric values. Subsequent to this
340
MN2.
THE
CANADIAN
AcKNowLEDGEMENTS
]::lmE(reWMSGS]:mMNA:IroEN
mn:mm@Mffio6
tu
cl
oH
r.
2.
d:
65.1
34.9
66.9
0.1
id
sFeinii@
lbeLi@l
of fr(cm),
rcr
@@€iri@
MINERALOGIST
63.1
14.6
d
3.
4.
Al:ffib
Mti€L
of affilG
59.5
L6.6
23.9
cf@ositu
det@id
The authors are grateful to several staff
members of the National Museums of Canada:
Mr. J. Van Velthuizen for preparing the X-ray
powder-diffraction patterns, Messrs. I. Wainwright and G. Young for the SEM photographs
und initial EDA, and Mr. R. Waller for the pH
measurements. We thank Dr. J'E. Dutrizac,
for providing Eh measurements'
CANMET,
Mr. J.M. Kukielka was particularly skilUul at
mounting and polishing single grains of spertinite for electron-microprobe analysis.
studynone grain, about 50 g,m in size and with
an X-ray pattern very similar to that of synthetic Cu(OH)2, was mounted, polished and
ReEnnnNcEs
anallzed quantitatively.The averageanalysis,i.e.,
as functhe values obtained for this grain and for the Gannl,Ls, R.M. (1954): Mineral species
tions of pH and oxidation-reduction potentials,
grains in the diopside matrix, is shown in Table
with special reference to the zone of oxidation
2, together with the analysis of the associated
and secondary enrichment of sulphide ore .deof
atacamite and the theoretical compositions
posits. Geoc&int. Cosmochinr, Acta 5' 153-168'
the two minerals.
GeNrsts
In the Jeffrey specimens, it appears that
spertiniite is a product of the supergenealteration of chalcocite. Three groundwater samples
were collected in the area where the spertiniite
was found. This percolating water was found
to be oxidizing, Eh - + O.83, which is to be
expected for groundwater, but it was quite alkaline, pH=9.2. These rather unique conditions
preclude the formation of copper sulfates,which
are the normal alteration products of chalcocite. In this range of Eh and pH, the solubility
is due almost entirely to the cupric ion, and
the stablesolid phaseis cupric hydroxide (Garrels 1954).
From the chemicalanalysisit is apparentthat
the spertiniite structure does not accept much
chlorine. Any chloride ions available in the
groundwater have been essential to the formation of atacamite.
GnrcE..J.D. & WIt-lteus, R. (1979): The Jeffrey
mine, Asbestos, Qu6bec. Mineral. Record 10,
69-80.
J,rccr. H. & Oswero, H.R. (1961): Die Kristallstruktur des Kuferhydroxids, Cu(O}I)2. Acta
Cryrt. L4' 1041-1045.
RucrclDcE, J.C. & GesrenmNl, E. (1969): EMPADR VIl. Specifications of a computer program for processing electron microprobe analytical data. Dep. Geol. Univ. Toronto.
WenEs, R.P. & MARTIN,R.F. ( 1980): Rodingitization of granite and serpentinite in the Jeffrey
mine. Asbestos,Quebec' Catt. Mineral. 18, 231240.
Wusr. R.C. (1977): Handbook ol Chemistry and
Physics (57th ed.). Chemical Rubber Publ. Co.'
Cleveland. Ohio.
Received October 1980, revlsed manuscript accepted
December 1980.