l'HF] AMERICAN
MINERAI.OGIST,
VOL. .55,\OVEMBER_DECEMBER,
19iO
CHEMICAL COMPOSITION AND PHYSICAL
PROPERTIBS OF PHILLIPSITE FROM THE
PACIFIC AND INDIAN OCEANSI
Rrcneno A. SnoppenD AND Anrnun J. Gunr, III,
U.S. GeologicalSwrney,Federal Center,Denaer,Coloratlo80225
AND
Jonu J. Gnrl'rrN, Scripps InsttLution oJ Oceanography,
La Jolla, California 92037.
ABSTRACT
Twelve new chemical analyses of deep-sea phillipsite show that this zeolite is alkalic
and has a Si/Al ratio of 2.M-2.79. Potassium is generally in excess of sodium. The Bao
content is 0.00-0.73 weight percent. The mean index of refraction for the analyzed phillipsites is 1 477-1.486, and an increase in the index can be correlated with an increase in the
Bao content and a decrease in the Nazo content. cell parameters for the analyzed phillipsites show the following ranges: a:9.92 10.06 A, b:14.11-14.20 it. c:14.18'1432 A,
and, V : 1.994-2 .027 La.
INrnotucrtoN
Phillipsite was first recognized in deposits on the Pacific Ocean floor
by Murray and Renard in 1891. Since then, this zeolite has becomea
commonly reported constituent of deep-seasediments.Large areas of
the Pacific Oceanfloor are coveredwith sedimentsthat contain concentrations of phillipsite that are locally in excessof 50 percent (Bonatti,
1963; Goldberg, 1963). Three chemical anall'sesgiven by Murray and
Renard (1891) showed that deep-seaphillipsites are alkalic and relatively siliceorls as conpared with phillipsites from mafic igenous rocks.
These chemical characteristics were supported by two more recent
analyses(Goldberg, 1961; Rex, 1967).
In the present study we give 12 new chemical analysesof deep-sea
phillipsites. The chemical compositions of these marine phillipsites are
compared with the compositions of phillipsites from other geologic
environments. we also attempted to correlate variations in the indices
of refraction and cell dimensionsof the deep-seaphillipsites with variations in their chemicalcompositions.
The phillipsites were separatedfrom cored and dredge-haulsamples
taken by Scripps Institution of Oceanography from widely scattered
Iocalitiesin the Pacific and rndian oceans (Table 1). The original core
samples contained 25 percent or less phillipsite, whereas the dredgehaul samples contained about 50 percent phillipsite. In addition to
phillipsite, the original samples consisted of clay minerals (chiefly
montmorillonite), hydrous iron-manganese oxides, qtartz, plagioclase,
r Publication authorized by the Director,
U.S. Geological Surve-v.
2053
20s4
RICHARD A SHEPPARD AND ARTHUR J. GUDE, II]
clinopyroxene, anatase, rutile, zircon, and siliceous and phosphatic
debris of organic origin. Relatively pure concentratesof the phillipsites
were made utilizing a heavy liquid mixture of tetrabromoethaneand
n, n- di meth.vlfor ma mid e.
Cuplrrcer- Colrposrrro x
The phillipsite concentrates weighed only 0.5 gram or less, so the
classical analytical techniques for silicate minerals could not be used.
The HzO content was determinedby weight lossafter heating at 1,000oC
for 30 minutes. Inasmuch as the samples did not contain a carbonate
mineral, the weight loss representsthe HzO content of the zeolites'
Tasr,r
Sample
No
1
2
.!
9
10
1l
l4
15
I7
18
2l
22
l. Locarrox asn Lrruolocv or Saupr,rs rnolt Wnrcr
AN,tt,vzro Prrrr-r-tpsrtos Wnnr Srper'erno"
Core or
dredge
haul
No.
JYNV-8G
JyN V-8G
Proal71G
Ris 80G
Ris 80G
Ris79G
Dodo113D
Proa I I
Dodo232D
Amph48PG
JYNV-49PG
Dodol13D
Locauon
Water depth
(in meters)
13"26lN.,152o17',W
l
1 3 o 2 6 ' , N1. ,. s 2 ' 1 7W
16043'N,165010'W
14"02/S , 134055'W
1 4 0 0 2 ' S .1, 3 4 0 5 5 ' W .
14"03'S.,131'44/W
23'16'S.,74'59'E
6 0 0 8 ' N ,"l . l 6 ' 1 1 ' E .
5"23t5,97"29'F'.
13'581S,161'03/W.
17o10',N,132o50',w
2 J o l 6 ' s, 7 4 o 5 s ' E .
5746
s 74 6
5.)50
4250
4250
4 11 0
4520
4600
4119
4 51 0
5188
4520
Sample Position
within core
(in centimeters
Irom top)
15-25
15-25
10-15
70-E0
70-80
-t0 {5
Unknown
20-25
30-45
Lithology
Light-brown clay
Light-brown clay
Light-brown clay
Dark-brown claY
Dark-brown claY
Dark-brown claY
Manganese-coatedboulder
Light-brown siltY claY
Manganese-coatedboulder
Light-brown and red claY
Dark-brown claY
Manganese-coatedboulder
e Sample Nos 14, 17, and 22 are from dredge hauls; all others are from cores'
Contents of the other constituents were then determined on the anhydrous residues.SiOz,AlzOs,FerOr, CaO, K2O, and BaO were deterThe NazO and MgO contents were determined by X-ray fluorescence.
mined by aLomic absorption becausethese constituents could not be
determined a.ccuratelywith the X-ray fluorescenceequipment at hand.
In order to recast the analyses(Table 2) to a hydrous base and correct
for FezOgimpurities, the following calculationswere necessary:(1) the
determinedHzO content of eachanalysiswas assumedto be correct, and
the other constituents were prorated to 100 percent minus the HzO content; (2) all FezOtwas assumedto be an impurity and was subtracted;
(3) the analyseswere then recalculatedto 100 percent and are given in
Table 3. The molecularratio lrbOs/ (Ca, Mg, Ba, Nar, Kz)O for zeolites
should be unity. This ratio is 0.96-1.10 for the corrected analysesof
deep-seaphillipsites. Most of the phillipsites that have a ratio greater
PHILLIPSIT]!
FROM THE OCEANS
Tenr,B 2. Cnnurcel ANlrrsns or Dnrt,-Sne Pnrlr,rpsrrrs'
'IlotaI
Sample
I
2
5
9
10
11
l4
l.)
17
18
21
22
('aO
SiOz
AlzOr
Ire:O:
60.4
60.2
630
s89
56.6
594
62 1
63.2
597
589
608
59.4
19.2
187
t9 2
19.1
19.2
19.3
21.6
207
20.3
202
1 8. 9
20.4
1 . 9 0 0. 70 0 .56 0 0 9
2.26
.86
60
08
1.80
.75 1 6.5
. 13
2 42
. 3 3 1. 3 1
.12
3.58
.34 1.28
.11
3.60
.22 2.47
2+
.48
09
.12
00
04
.02
02
00
2 rJ4
63
90
.08
295
. 3 6 6 .t 0
.78
4. 7 3 1 . 4 0 l . 0 8
.80
1.90
.76 1.11
31
NISO
Nuro
KrO
(anhp
(trousl
4.71
4.50
3 .3.5
4.20
4.08
3.02
6 .58
6..5.5
6 05
1. 2 6
2.30
4.82
7 .68
7 .42
7 61
8.22
7.98
7.55
8 71
8..57
7. 3 3
.i.41
6.75
7.41
95 24
94 62
97 49
94.60
93.17
95.80
99.68
99tO
9 7. 0 3
95.96
96.76
96.11
Hs0
14.4
13.9
15.3
15.5
r4.9
r5 I
16.8
15.3
16.1
17.1
15.0
t4.3
"HrO determined by J S. Wahlberg b1.-weight Joss at 1,000'C. SiOz, AlzOa, lerOa,
CaO, BaO, and KzO determined bf'J. S. Wahlberg b1' ;1-.u" fluorescence on anhydrous
residues. NazO and MgO determined by Wayne Mountjoy by atomic absorption on anhydrous residues.
than unity'have a ratio of 1.03or less.fnasmuch as only two phillipsites
have a ratio less than unity, substitution of ferric iron for aluminum
seemsunlikely in thesezeolites.The assumptionthat the anal-vzedFezOs
is an irnpuritl- is justified.
Unit cell contents (Table 4) were calculated frorn the corrected
analvses in Table 3 on the basis of 32 oxr-gen atoms. The Si/Al ratio
Tesln 3. Conr,nc:rnn
Cnpurclr,CouposrrroNs
or I)nnr,-Su Pgrlr,rpsrrEsu
Sample
I
2
.)
9
10
11
l4
15
tt
18
21
22
\{gO
55.23
5 5. 9 2
5560
53.78
s3.46
54.38
52.05
s4.03
s2.54
52.22
5 5. 7 2
53 89
CaO
NotO
KzO
1 7 5 7 0 6 4 0 5 1 0 0 8 4 . 3 0 7 . 0 2 I't. 6.5
1 73 8
.8 0
.56
.07 1 1 9 6 8 9 14.19
1 6 . 9 5 6 7 1 -46
1 l 2 9 6 6 . 7 1 15.54
r7 44
.31 t20
. 1 0 3 83 7..50 r5.84
18.13 32 121
1 0 3.8-1 7 54 15.40
17.66 .2r 2 . 2 6 .22 2 . 7 6 6 . 9 r 15.60
18.09 .08 . 1 0
. 0 0 5 . 5 1 7 3 0 16.87
t7.70 .02
.02
. 0 0 5 . 6 0 7 . 3 3 15 30
70
t7.87 .56
. 0 7 5. 3 3 6 . 4 5 1 6 . 3 9
r 7 . 9 0 . 3 2 5. 4 1
, i o 1 . 1 1 4 7 9 17.55
1 7. 3 3 1 2 8
99
2 . 1 1 6 . 1 9 15.65
18 50
69 1 0 1
2i
137 672
14.5s
100.00
100.00
100.00
100.00
100.00
100.00
100 00
100 00
100.00
1 0 00 0
1 0 00 0
100.00
n Analyses froni 'fable 2 were recast to a h;'drous base, liezOawas suLtracter-I,and then
the analyses rvere recalculaLedto 100 Dercent.
2056
RICHARD A. SHEPPARD AND ARTHUR J. GUDE, IIl
Ta.slr 4. Uut Cer,r,CoNrrNm lon Dnrp-Sea Pnrr-r-rpsttts"
Sample
1
2
9
10
11
t4
IJ
11
18
2I
22
Si
Al
Mg
Ca
Ba
Na
K
r r . 6 5 4 . 3 7 0 . 2 0 0 . 1 2 0 . 0 1 1. 7 6 1 . 8 9
.25 .t2
. 0 1 1. 7 0 1. 8 4
t 1 . 71 4 . 2 9
.2t
. 3 3 . 0 1 | . 2 2 1. 8 1
tt.79 4.23
1r.58 4.42
.10 .28 .01 1.60 2.06
.28 .01 1 60 2.06
1146 458
.1 0
11.614.M
.07 .52 .02 1.14 1.88
.02
.00 2 . 3 4 2 . 0 4
1138 466
.03
rr.56 4.46
.01
.01 .00 2.32 2.00
11.394.56
.18 .18 .01 2.24 r.78
.06 .47 1.33
11.38 4.60
.10 |.26
.40 .22 .06 .86 t.67
tt.78 4 32
tt .40 4.61
.22 .23 .02 r.79 1.81
H:O
Si/Al
Si+Al
10.31
9.9t
10.99
rr .37
11.01
11.11
t2.3r
10.92
11.85
t2.76
11.04
r0.27
2.67
2.73
2.79
2. 6 2
2.50
2.61
2.M
2.59
2.50
2.47
2.73
2.47
16.02
16.00
16.02
1 6 .0 0
16.04
16.0s
16.Ot
16.02
15.95
15.98
1 6 .1 0
16.01
" Calculated in atoms per unit cell on the basis of O:32.
ranges ftom 2.44 to 2.79. Monovalent cations are in excessof divalent
ones; the sum of the divalent cations is generally less than 0.5 atom per
unit cell. Potassium is generally in excessof sodium.
The compositions of deep-seaphillipsites and phillipsites from other
geologic environments are represented in Figure 1. Although there is
slight overlap, the phillipsites can be classed into three groups on the
basis of Si/Al ratios. The least siliceous group is from mafic igneous
rocks and is characterizedby a Si/Al ratio of about 1'3-2.4. Phillipsites
of this group commonly have a higher percentageof alkaline earths than
those of the other two groupsl some specimenshave alkaline earths in
excessof alkalis. The most siliceous group has a Si/Al ratio of about
2.6-3.4,although most have a Si/AI ratio greaterthan 3.0. Thesesiliceous
phillipsites are from silicic tuffs in saline lacustrine deposits and are
characteristically very high in alkalis. The deep-seaphillipsites comprise
an intermediate group and have a Si/AI ratio of about 2.3-2.8' Like the
lacustrine phillipsites, these deep-sea phillipsites are rich in alkalis;
however, the two groups differ in the predominant alkali. All reported
lacustrine phillipsites show sodium in excessof potassium (Hay, 1964;
Sheppard and Gude, 1968), but deep-seaphillipsites commonly have
potassium in excessof sodium.
Although barium-rich phillipsite or harmotome (a barium zeolite)
has been reported as being widespread in the sea-floor deposits (Arrhenius, 1963,p. 698-701), the analyzed samplesof this study are not particularly rich in barium. The BaO Content of the 12 analyzed'samples
(Table 3) rangesfrom 0.00 to 0.73 weight percent; however, most of the
analyzed phillipsites have a BaO content of less than 0.3 percent
PHILLIPSITE
FROM THE OCILANS
r 4 - R- r 5
2057
lo "6p
j'r.^+ o o
o
^'
"i^l 'L^
o
"A
a
o
d)
-a
+
a
o
:< ?
+ I
o
z +
Y
+
z
a
1
a
a't
a
a
o.50
oo
0.25
Si/AI
Frc. 1. Plot showing the compositional variation of phillipsite. Open circle, phillipsite
from saline lacustrine deposits; solid triangle, phillipsite from deep-sea deposits; solid dot,
phillipsite from mafic igneous rocks. Numbered triangles are the analyses listed in Tables
3 and 4. Sources for analyses represented by lettered triangles are: M. Murral' and Renard
(1891) and R, Rex (1967).
Puysrcer PnopBrrms
Phillipsites from the deep-seasediments occur as elongated, prismatic
crystals that are chiefly subhedral to euhedral (Fig. 2). Individual
crystals range in length from lessthan 8 pm to about 250 p,m; most, however, are 10-120 prmlong. When viewed under crossednicols, the "individual crystals" are shown to have a complex sector twinning that simulates single crystal forms. Cruciform twinning is relatively rare. The
analyzed phillipsites are colorlessto yellowish brown, depending on the
abundance of minute isotropic inclusions. Inasmuch as the value (lightness) of the color can be correlated with the FezOr content shown in
Table 2, the inclusions are probably amorphous iron oxides. Large
phillipsites commonly show a zonal distribution of the inclusions.
Index of Refraction. The mean index of refraction of the analyzed deepsea phillipsites has a relatively narrow range, I.477-1.486t0.00t
(Table 5), and the birefringenceis low, about 0.002. Phillipsite Irom
20.58
RICIItIRD .'t SIIEPPARD ANI) lllT'HLrR J. GUDIi. III
Frc. 2. Photomicrographof a typical concentrateof prismatic phillipsite from core No.
Ris 80G (sampleNo. 10). Unpolarizedlight.
various rock t)'pes and geologic environments show a range in the mean
index of refraction of about 1.44-1.5i. Hay'(196a) found that the index
of refraction of natural phillipsites decreases with an increase in the
Si/Al ratio. Phillipsites with Si/AI ratios less then 2 commonh' have
indices of 1.48-1.51, whereas phillipsites with Si/Al ratios of 3 or greater
have indices oI 1.44-1.48. Thus, the deep-sea phillipsites fit this general
Talr,r 5. MRIN INnox or ltnrnacrtoN lxn Cnr,l P.lnalrnrrns
ron I)nnp-Sra Pmtlrpsrtn
Sample
No.
1
2
.5
9
10
11
I+
IJ
1l
18
2l
22
Mean index
of refraction
7 (A')
d (A)
(+0.001)
t.482
1. 4 8 1
1.485
1.483
1.484
1 .486
1 477
1.478
1.480
1.485
1 486
1.483
10.003(2)
e e62(2)
e.e28(6)
e .e7s(r6)
9.981(6)
9.960(7)
9 974(6)
e.97o(r4)
e .e80(6)
10.00s(3)
e.e46(4)
e.974(4)
14.1s6(3)
14.260(2)
14.169(2)
14.243(2)
t4.14r(20)
14.221(6)
14.1,82(19) 14.274(2e)
1 4 .1 7 s ( 1 0 ) 14.1e8(6)
14.133(10) 14.208(s)
t 4 . 1 74 ( 8 )
14.307(r7)
14.16s(r2)
14.264(9)
14.161(6)
14.248(4)
14.182(4)
14.282(4)
14.12s(8)
14.260(6)
r + . 1 2 4 ( 1 8 ) 14.290(4)
20re.4(s)
2010.3(4)
re96.6(26)
2019.4(41)
2008.7(13)
1999.9(16)
2.22.6(2s)
2014.4(3o)
2013.6(12)
(7)
2026.7
2003.3O)
2Or3.s(23\
P 1.1
I LLI P,9IT I' ]IItOJIf 7'II ]i OC1'A N.S
a
t.486
z
o
F
o
G
r
lrJ
E.
u_
2059
a2l
a-
1.484
o
t8
alo
a9
| 482
a22
al
a2
x
lrJ
z
at7
| 480
z
tt
t5
t.4
t4
1.476
o
o.2
04
0.6
W E I G H TP E R C E NB
To O
0.8
Frc. 3. Variation in the mean index of refraction versus the BaO content for deeo-sea
phillipsite. Numbers indicate samples listed in Tables 3 and .5.
pattern inasmuch as the)' have intermediate Si/Al ratios and intermediate indicesof refraction.
An attempt was made, without success,to correlatethe mean indices
of refraction with the Si/Al ratios of the deep-seaphillipsites. However,
the indices seem to be afiected by the barium and sodium contents. A
plot (Fig. 3) of mean index of refraction versus weight percent BaO
suggeststhat an increasein the barium content can be correlated with an
increasein the index of refraction. The effectseemsmost pronouncedfor
BaO contents less than 0.2 percent. BaO contents greater than 0:2 percent seemto causeonly a slight additional increasein the index. Figure 4
is a plot of the mean index of refraction versus weight percent Na2O
and suggeststhat an increasein NazO content correlateswith a decrease
in the index of refraction.
Cell' Parameters. Cell dimensions and volume for the ana.Iyzeddeep-sea
phillipsites (Table 5) were obtained by a least-squares refinement of
X-ray powder diffractometer data utilizing the U.S. Geological Survey's
FORTRAN IV Computer Program W9214. The spacegroup and initial
orthorhombic cell parametersused were rhose of Steinfink (1962). Cell
parameters for the analyzed phillipsites show the following ranges:
a:9.92-10.06 A, 6: t4.tt-14.2o A. c - 14.18-t4.32A, and V :19942 0 2 74 3 .
RICIIARD A. SHEPPARD AND ARTIIUR J. GUDE, III
t.486
z
o
F
c?t
o'l
a5
t.484
a
t
U
(l
o22
a9
L
t.482
ol
L
x
U
o
z
a2
| 480
ol7
z
U
t.478
aa
t4
| 476
34
W E I G H T P E R C E N TN o 2 O
Fro. 4 Variation in the mean index of refraction versus the NarO content for deep-sea
phillipsite. Numbers indicate samples listed in Tables 3 and 5.
There seems to be no correlation between the compositions of the
deep-sea phillipsites and their cell parameters. Furthermore, alkalic
phillipsites with Si/Al ratios of 3.2-3.3 (Toribio Manzaneres, Jr., oral
commun., 1970) and a calcic phillipsite with a Si/Al ratio of 1.7 (Iijima
and Harada, 1969) have about the same cell parameters as the deep-sea
phillipsites. These data suggest that variations in chemical composition
have slight or no effect on the cell parameters of natural phillipsite.
Drscusstow
Phillipsite in the deep-seadeposits probably formed during diagenesis
by the alteration of volcanic debris (Murray and Renard, 1891;Bonatti,
1963). Although basaltic glass was probably the ultimate precursorfor
the phillipsite, palagonite may have been an intermediate alteration
product. The composition of the parent material is known to affect the
composition of the zeolite (Mumpton, 1960). Thus, the difference in
Si/Al ratios between authigenic phillipsite of deep-sea deposits and
authigenic phillipsite of lacustrine deposits can be attributed to the
difference in the composition of the parent materials. Most authigenic
phillipsites in lacustrine deposits formed from silicic glass, chiefly of
rhyolitic compsotion. These phillipsites have higher Si/AI ratios than
the deep-seaphillipsites which are of basaltic parentage.
Phillipsites in both deep-seaand lacustrine deposits are alkalic, but
the deep-seaphillipsites are generally more potassic than the lacustrine
PHILLIPSITE
FROM TIIE OCEANS
2061
ones. Rhyolitic glass has a Na/K ratio of about 0.5, whereas basaltic
glass (Moore, 1966;Hay and Iijima, 1968) has a Na/K ratio of about
2-3. Palagonite,however,has a Na/K ratio of about 0.3 (Moore, 1966).
If phillipsite in the deep-seadeposits formed from palagonite, as Bonatti
(1963) has suggested,its potassic character could have been inherited
from the relatively potassic palagonite. The Na/K ratio of the fluid
phase from which phillipsite crystallized should also influence the cation
content of the phillipsite. Most of the phillipsites in lacustrine deposits
formed in sodium carbonate-bicarbonatewaters. These waters generally
have a Na/K ratio greaterthan 30 (Ha1-,1964p. 1381).Seawater has a
Na/K ratio of about 28 (Culkin, 1965), but interstitial water squeezed
from modern oceanic sediments is more potassic and has an average
Na/K ratio of about 20 (Siever et al'., 1965).Thus, there also seemsto be
a correlation between the sodic Iacustrine phillipsites and relatively sodic
waters and between the potassic marine phillipsites and relatively
potassic waters.
Acrxowr.npcurxrs
This work was in part supported by a contracl between the Office of Naval Research
and the University of California at San Diego. D. A. Brobst and H. C. Starkey critically
read the manuscript and made helpful suggestions.
RpltnrNcos
Annrrnuus, G. O S. (1963) Pelagic sediments. InHill,M. N., ed., TheSeo,3, Interscience
Publishers, New York, 655-727.
Boxarrr, Ennrco (1963) Zeolites in Pacific pelagic sediments. ly'ezu York Aca.d'. Sci'.
Trans., ser. I I, 25, 938-948.
(1965) The major constituents of sea watet. In J. P. Riley, and G'
Curnru, Fnnotmcr
Skirrow, eds.,Chemical Oceanogrophy,l, Academic Press, London, 121-16l
Gor,osnnc, E D. (1961) Chemical and mineralogical aspects of deep-sea sediments.
P hys. Chem. Ear th, 4, 281-302.
(1962) Mineralogy and chemistry of marine sedimentation. In F. P. Shepard,
S ubmarin e Geol'ogy, Znd' ed., Harper and Row, New York, 435-466.
Hrv, R. L. (1963) Phillipsite of saline lakes and soils. Amer. MineraL- 49, 136G1387 '
lNn Azuue IrrIIm (1968) Nature and origin of palagonite tuffs of the Honolulu
Group on Oahu, Hawaii. Geol. Soc.Amer. Mem.,l16' 331-376.
1;ru.t, Azuua, auo Klzuo Hexeo.q (1969) Authigenic zeolites in zeolitic palagonite tufis
-
on Oahu, Hawaii. Amer. MineroJ.54, 182-197.
Moom, J. G. (1966) Rate of palagonization of submarine basalt adjacent to Hawaii. 1z
Surwy. Prof . Pap.550-D, D163-D171'
GeologicalSurvey research 1966, {/.S. Geotr.
Munrrron, F. A. (1960) Clinoptilolite redefined.Amer. Mineral,45' 351-369'
Muntev, JonN, .txo A. F. RrNlnn (1891) Report on deep-sea deposits' Report on the
Scient'ffic Resdts of the Voyage of H.M.S. Challmger Dwing theYears 1873-76,Neill
and Co., Edinburgh, 520 p.
Rnx, R. W. (1967) Authigenic silicates formed from basaltic glass by more than 60 million
years, contact with sea water, Sylvania Guyot, Marshall Islands. Clays CIay Minerals,
Proc. Nat. ConJ.,15 (1966), 195-203.
2062
RICHARD A. SHEPPARD'AND
ARTHUR T. GUDE.. III
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