m=20.180
r=1.5
Where Fe2+
and Fe3+ would
fall if they were
hard cations
20 21 22
18
Ar
Argon
23
K+ 19 Ca
Calcium ion
4
4–
phosphate (PO43–
and HPO42– )
45
40 42 43
(48)
44 46 48 ?
m=83.80
r=1.9
Strontium ion
m=85.468
r=1.48
m=87.62
r=1.13
78 80 82
83 84 86
2+
Cs+
89
3+
La &
REEs
86
Radon
(222)
very rare
(<30 g in crust)
219 220 222
223 224
226 228
223
5771
227 228
93 (96)
92 94 96 ?
4+
5+
72
Hafnium ion
Hf
73
Tantalum ion
Ta
W
Mineral of
two cations:
210
Perovskite
Tungsten (Wolfram)
e.g., as tungstate
174 176 177
178 179 180
4+
90
Thorium ion
Th
m=232.038
r=0.95
180 181
180 182 183
184 186
Pa5+
U
91
Protactinium ion
(231)
(+3 r=1.14)
(+4 r=0.98)
227 228 230
231232 *234
231 234
6+
92
m=238.029
r=0.7
234 235*238
Al
Periclase
160
Perovskite
Tausonite
175
Rb
+
Sr
2+
4+
3+
58
Cerium ion
Ce
48
Cadmium ion
In
Cd
1,3+
m=74.922
r=0.69
49
94
96 98 99
100 101
102 104
99
(100)
103
4+
4+
4+
76 Iridium ion77
Osmium ion
75
Rhenium ion
Ir
Os
Re
95: Americium
96: Curium
97:Berkelium
98 Californium
99: Einsteinium
100: Fermium
Uranium ion
Plutonium
r=0.97
Very limited Very limited
natural
natural
occurrence occurrence
on Earth
on Earth
101: Mendelevium
102: Nobelium
103: Lawrencium
104: Rutherfordium
105: Hahnium
102 104 105
106 108 110
2+
78
Platinum ion
Pt
107 109
Au+
79
Gold ion
106 108 110
111 112 113 113 115
114 116
+
+
81
Hg 80 Tl
112 114 115 116
117 118 119
120 122 124
z /r
Mercuric ion
r=1.10
=4
Plumbic lead
Thallic thallium
=
z/r
"Soft" ("Type B") Cations
121 123
63
Europium ion
59 Nd 60
Praseodymium ion Neodymium
ion
3+
61 Sm3+ 62 m=151.964 Gd 3+ 64
Samarium ion
Tb
r=1.03
Promethium
Gadolinium ion
3+
66
65
Dysprosium ion
Terbium ion
Pm
3+
Dy
Ho
67
C
4+
N
NaNO3
MgAlBO4 Me2+CO3 (Soda Niter)
Minerals with
(e.g.,
(Sinhalite)
KNO3
1+
cations only
Calcite)
(Nitre)
Si
4+
P
5+
S
6+
Cassiterite 4+
Sn
As
588
Tenorite
1903
0
3+ Hematite
2+
3+
0
2
3+
0
2
Mn
0
0
Cu
1
Co
Paramont- Eskolaite 1353(d) Fe
Argutite Arsenolite
Zincite
1719
1168
(d)
1838
3+
3+
roseite 4+
4+
3+
2+ Ga
As
Cr
Bunsenite
Ge
V
2+
2+
Zn
2+
2+ Cuprite
547
2079
1388
2240 2603
Fe
Mn
Co
Cu + 2242
Ni
2400 2054 1652
2078 2228
1509
Romarchite Valentinite
Monteponite
Manga- Wüstite
2+
4+
3+
2+
2+
3+
+
3+
2000 Mo nosite 1600
Ag
Sn
Rh
Pd
Cd
1373(d) 1023(d) ~473(d) >1773
1373(d)
Tugarinovite
4+
Rh
~1773(d) 1173(d)
See also Inset 3.
In
2185
1353(d)
Sb
928
Ir
Pt
Hg +
423(d)
373(d)
2+
2+
1273 (d) 598(d)
+
Au
Hg
Tl +
852
Tl
3+
Massicot Bismite
2+
3+
Pb
Bi
1170
1098
no stable 773(d)
oxide Montroydite1107
Avicennite
Li
Cations
H+
N
Nickel
Copper
Zinc
33
34
As
Se
Arsenic
53
as phosphide
As
33
Arsenic as arsenide
Selenium
m=74.922
r=2.22
r=1.48 r=1.6
46
47
48
49
50
51
52
Ru
Rh
Pd
Ag
Cd
In
Sn
Sb
Te
Tin
Antimony
Cadmium
Indium
3–
Sb
51
Antimony
as antimonide
r=1.34 r=1.34 r=1.37 r=1.44 r=1.56 r=1.66 r=1.58 r=1.61 r=1.7
121 123
77
78
79
75
76
80
81
Ta
Re
Os
Ir
Pt
Au
Hg
Tantalum
Rhenium
Osmium
Iridium
Platinum
Gold
Mercury
82
Tl
Thallium
83
Bi
Pb
Bi
Lead
Bismuth
19
–
16 ClChlorine17
2–
Sulfur as sulfide
as choride
32 33 34 36
2–
2–
83
Bismuth as
bismuthide
m=208.980
35 37
34
Se
–
Br
Selenium
as selenide
(7+ r=0.39)
79 81 (82)
Tellurium
as telluride
–
53
Iodine as iodide
m=126.904
r=2.16
m=20.180
r=1.5
20 21 22
36 38 40
m=83.80
r=1.9
78 80 82
83 84 86
z /r
54
Xe
Xenon
m=131.29
r=2.1
124 126 128
129 130 131
132 134 136
124 125 126 (124) 127
(128) (130)
128 130
The only bismuthide
minerals are of
Pd, Ag, Pt, Au, and Pb
36
Kr
85
86
Rn
Radon
Astatine
(222)
r=1.46 r=1.37 r=1.35 r=1.35 r=1.38 r=1.44 r=1.60 r=1.71 r=1.75 r=1.82
=1
18
Ar
m=39.948
r=1.8
(7+ r=0.50)
At
Neon
Krypton
m=79.904
r=1.95
I
10
Ne
Argon
35
Bromine
as bromide
m=78.96
r=1.98
74 76 77
78 80 82
Te 2– 52
34
Anions with
which hard cations
preferentially
coordinate
16 17 18
m=127.60
m=121.760 r=2.21
r=2.45 120 122 123
Tellurium
as a solute in seawater
because it speciates
both as I– (to right)
and IO 3– (here).
73
m=15.999 m=18.998
r=1.36
r=1.40
15 S
Phosphorus
3–
45
Silver
–
F Fluorine 9
O
8
as fluoride
Oxygen as oxide
m=28.086 m=30.974 m=32.066 m=35.453
r=2.71
r=1.81
r=1.84
r=2.12
44
Ruthenium Rhodium Palladium
m=1.0079
r=2.08
123
218 219
220 222
215 218 219
r=0.74
4
Version 4.6a12 © 2003 L. Bruce Railsback, Department of Geology, University of Georgia, Athens, Georgia, 30602-2501 U.S.A. ([email protected])
This table should be accompanied by explanatory notes and references. For updates and more information, see http://www.gly.uga.edu/railsback/PT.html.
Inset 2: Hardness of oxide minerals of hard cations
3+
68
Erbium ion
3+
Tm
3+
70
Ytterbium ion
3+
Yb
69
Lu
+
Li
71
2+
Be9
B
3+
4+
C
N
5+
176Hf
+
Mg
Al
Si
4+
7
Quartz
P
5+
S
6+
Ab
Na
Anion:
F–
Mineral
Nonmineral
Cl–
Br–
I–
(AgI)
10-8
HgBr2
HgI2
10-6
10-4
Ag+(
Na+(
Lime
Halite
(NaCl)
MgCl2
(AgBr)
2+
Ca3.5
10-2
5.5
AgF
HgCl2
Bromargyrite
Iodargyrite
(NaF)
(MgF2)
(AgCl)
+
Villiaumite
Sellaite
Chlorargyrite
K
Perovskite
+
MgBr2
NaBr
MgI2
NaI
1
100
Hg2+(
*
(Ru=6-6.5)
)-,
)-,
Solubility of
2+
)-, and Mg ( )-bearing halides (mol/L)
Mineral of
2+
one cation:
7
Quartz Hardness
Sr
Mineral of
two cations
5.5
Y
V 5+
3-3.5
Shcherbinaite
Srilankite
6.5
3+
4+
5+
Zr 6.5
Cr 6+
Nb
Baddeleyite
Mo
K
3-4
Molybdite
2+
----Di An
+
Rb
Mg
Fe
Ca2+
3200
Bi
6+
B
+
673
Sr
2+
2938
3+
C
723 En
2+Fo
3125
1193
Ksp
Ti 4+
>9
Be
2+
2681
1700
Chrysoberyl
8.5
2+
+
3+
Spinel
Periclase
7.5-8 9
5.5-6
Corundum
Na
Inset 3: High-temperature behavior of hard cations
Li
Bromellite
Inset 8: Solubility of halides
of hard and soft cations
1Å
High z/r
Strong
O2–
Rb
bonds, but
Intermediate cation-cation
Low z/r
repulsion
z/r
Weak cation- Strong cationoxygen bonds oxygen bonds
3–
m=4.0026
r=1.2
An Earth Scientist's Periodic Table of the Elements and Their Ions
Er
Inset 7: Conceptual model of the behavior of
oxides of hard (and intermediate) cations
Silicon as silicide
4+
216
Ab
Al 3+
Si
2345
4+
An 1996
Q
Ti 4+
5+
N
500
P
5+
S
855
6+
290
Cr
Il
3+
Cr
-----
Sc
Y
3+
Ti
4+
Ti 2103
V
5+
943
10
3+
Zr
4+
3123
Nb
5+
1785
6+
Cr
00
Mo
6+
1074
(Mohs
scale)
La 3+ Hf 4+ Ta 5+
Perovskite
*A non-rutile synthetic TiO2
is the hardest known oxide
7
Tantite
Th
Thorianite
6
5+
W 6+
Cs
+
Ba
2+
2286
La
3+
3173
2580
See also Inset 6.
Hf
4+
Th
5+
3493
Ta
5+
2058
W
Cation
(outlined for
intermediate
cations)
Melting T (K)
2103
of oxides of
hard cations
Minerals are shown with size
of circles representing
proportions of cations.
Minerals in order of typical
temperature of formation*:
3+
Fe
-----
6+
1745
1500
W
4+
3+
3+
Au
Zn
3000
Minerals
with
Minerals with
1+ to 4+ cations 1+ to 3+
cations
with
1+ & 2+
cations
5+
Si 14 P
2000
2500
0
300
KAl2Si3O8 (Kspar) Na3PO4 CaSO4
(Olympite) (Anhydrite)
Al2 SiO5 (K-S-A)
Na2SO4
AlPO4
ZrSiO4 (Zircon) (Berlinite)
(Thenardite) Minerals
"K-S-A"
indicates
kyanite,
andalusite,
& sillimanite.
Inset 6: Melting and decomposition (d) temperatures
(K) of oxides of intermediate and soft cations
00
16
5+
Cu
Substitutes for Ca2+
z/r = 2
3+
Ni
(Atomic masses
and isotopic
information
are omitted to
conserve space)
1
2
83
Thulium ion
m=173.04 Lutetium ion
Lantham=140.908 m=144.24 No natural m=150.36 151 153
m=157.25 m=158.925 m=162.50 Holmium ion
m=167.26
m=164.930 r=0.96
r=1.04
nides: m=138.906 m=140.116 r=1.09
m=168.934 r=0.94
occurrence
m=174.967
r=1.08
r=1.02
r=0.99
2+
(2+
r=
1.13)
r=1.00
r=0.97
r=1.15
(4+ r=0.92)
r=0.95 168 170 171 r=0.93
63 152 154 155
r=1.11
156 158
142 143 144 on Earth 144 147 148 Eu
162 164 166
?
175 176
156 157
149 150
160 161 162
146 145
172 173
136 138 140
Europium ion
169
165
167
168
170
?
138Ba
159
141
138 139
(150)
?
158 160
148 150
142
152 154
163 164
174 176
r=1.12
Lanthanum ion
30
r=1.26 r=1.25 r=1.24 r=1.28 r=1.39
Iodine
as iodate (IO3– )
84
Rare earth elements (REEs)
(effectively "Hard" or "Type A" cations in their 3+ state)
Eu
Cobalt
29
Hydrogen
as hydride
Helium
Bismuth ion
Coordinate I>Br>S>Cl=N>O>F
3+
5+
I
210 211 212
209 210 211 214 215
212 214 215
216 218
Bi5+
(Many electrons remain in outer shell)
3+
14 15
75
Polonium
m=208.980
r=1.20
r=0.84
r=0.95
2
120 122 123
124 125 126
128 130
3+
2+
Bi
83 Po
82
Pb
Bismuth
ion
Plumbous lead
Thallous thallium
Mercurous ion
=
z /r
239
Pr 3+
52
Tellurium ion,
Te
Sb
m=192.217 m=195.078 m=196.967 m=200.59 m=204.383 m=207.2
m=190.23
m=186.207
r=1.40
m=183.84
r=1.20
r=0.66
r=0.69
r=0.96
r=0.65
r=1.37
r=1.19
r=0.64
184 186
190 192 193? (3+ r=0.85) 196 198 199 203 205 206 204 206 207
180 182 183
200 201
187 188 189 191 193
194 195
208 210 211
184 186
185 187
197
202 204 206 207 208 210
196 198
212 214
190 192
4+
Hg2+ 80 Tl 3+ 81 Pb4+ 82
U
92 Elements 95 and beyond do not occur naturally:
185 187
4+
3+
50 Antimony51
ion,
Sn
Indium ion
75
28
Co
Iron
r=1.27
4–
Sulfur
Silicon
He
–
Most natural occurrences of carbides and
nitrides are in meteorites or mantle phases.
r=1.43 r=1.34
0
145
57
Silver ion
2+
Chromium
m=78.96
r=0.50
74 76 77
78 80 82
27
Fe
Cr
e.g., as selenite
as in tellurites
Stannous tin
as in antimonites
m=101.07 m=102.906 m=106.42 m=107.868 m=112.411 m=114.818 m=118.710 m=121.760 m=127.60 m=126.904
3+ r=0.81
3+ r=0.69
r=0.86
r=0.97
r=0.44
r=1.26
r=0.89 Iodine
r=0.90
1+
r=1.32
r=1.12
r=0.86
4+ r=0.67
is shown twice
Very limited
natural
occurrence
on Earth
58
r=1.01
47
69 71
70 72
73 74 76
2+
33
Arsenic
e.g., as arsenite
(2+ r=0.93)
(1+ r=1.13)
34
Selenium
Se
Aluminum
2500
Hf
4+
Ruthenium ion
46
Palladium ion
Pd
Ag +
m=72.61
r=0.53
4+
Reduced nitrogen
m=12.011 m=14.007
r=2.60
r=1.71
16
S
Al Si
200
La
3+
*Baddeleyite has
Ks = 95 GPa but
is not the most
stable ZrO2 phase
at ambient conditions; value shown
is for the latter.
Technetium
45
Rhodium ion
m=69.723
r=0.62
As
26
24
1500
71
5+
54 56 57 58
2+
Ru3,4+44 Rh
r=0.96
63 65
3+
r=0.56
H=6
0
Ba
La
B
Nb
Y 1 Zr
50
152*
87
2+
3+
5+
200
3+
4+
Ce
4
Inset 5: Typical simple oxysalt minerals
(__MOn minerals without OH or H2O)
Rutile
10
Cs
+
V
74
Tungsten (Wolfram)
ion
?
Reduced carbon
7
The only known natural occurrences of
phosphides and silicides are in metorites
and cosmic dust.
4
Lime 115
Ti216
4+
59
43
Cerium ion
5+
50
55
58 60
61 62 64
2+
r=0.62
e.g., as tellurate
14
13
other than noble gases
H=
210
4+
P
W
r=0.76
m=65.39
r=0.74
64 66
67 68 70
51
e.g., as antimonate
Germanium ion
Gallium ion
Zinc ion
Sb5+
r=0.42
Te6+ 52
4
Ca
2+
38
Quartz
m=95.94
r=0.68
2+
2+
30 Ga3+ 31
Zn
r=0.69
r=0.71
Ge4+ 32
r=0.47
Principal elements in iron
meteorites (Fe>>Ni>>Co) and,
with S or O, presumably dominant elements in Earth's core
as selenate (SeO42–)
H=
K
+
Si
r=0.73
50
Stannic tin
3–
4
8
198 254
Corundum
4+
8
r=0.63
z =
/r 8
z
/r =
3
Chrysoberyl
240
2+Spinel 3+
r=0.80
r=0.90
Mo4+ 42 Tc
75
Rhenium ion
237
4
2+
+
28
29
27 Ni Nickel ion Cu
Co
50 52 53 54 Mn 25 Fe
26
Cuprous copper
Cobaltous
cobalt
Manganous Mn
Ferrous iron
m=58.693
2+
m=63.546
24 m=54.938 m=55.845 m=58.933
CrChromous
r=0.72
r=0.74
Molybdenum ion
93 Pu
Sn4+
2–)
6 N
12 13 14
(uncharged)
6
Mg
C
4+
50 51
r=0.64
2+
2+
chromium
Re7+
Neptunium
Uranium, e.g.
as uranyl (UO22+)
m=51.996 4+ r=0.53
r=0.69 3+ r= 0.64
92 94 95 96
97 98 100
Np
r=0.37
3
34
Se
H=
Na
B 3+
251
Bromellite
+
2+
Nonmineral:
71
m=50.942
r=0.74
r=0.90
z
/r =
/r = 8
33
arsenate (AsO )
As
H=
Be
Ti 22
23
VVanadous
vanadium
m=178.49
m=186.207
m=180.948
m=183.84
r=0.81
r=0.56
r=0.73
r=0.68
e.g., as tantalate
z/r = 2
÷
ge s
har diu
ic c c ra
ion ioni
z/ = 1 =
r
Inset 1: Bulk modulus (Ks in GPa)
of oxide minerals of hard cations
r=0.61
Titanium ion
z
chromium
3+
r=0.75
2+
z
/r
=
74
*For the sake of simplicity,
the 235U-207Pb and
232Th-208Pb series are omitted.
Li
Titanium ion
VVanadium ion
m=95.94
r=0.62
92 94 95 97
96 98 100
6+
O2
N2
See also Inset 7.
C
Diamond Molecular Molecular
& graphite nitrogen
oxygen
Elemental Forms
8
124 126 128
129 130 131
132 134 136
+
Ti 22
e.g., as molybdate
m=92.906
r=0.70
90 91
m=132.905 m=137.327
r=1.35
r=1.69
See below
130 132
134 135 136
170Yb
133
137 138
2+
Ac 3+ 89
Fr +
87
Ra
88
Actinium ion
Francium ion
Radium ion
m=227.03?
(223)
(226)
r=1.18
r=1.40
r=1.76
m=131.29
r=2.1
Mineral of
one cation:
38
Quartz
3+
chromate (CrO4 2–)
8
7
Metals
z/ r=
55 Ba
56
Barium ion
Cesium ion
Niobium (or
Columbium) ion
m=88.906 m=91.224
r=0.80
r=0.93
84 86
87 88
85 87
54
Xenon
Yttrium ion
Coordination with S or O likely
3+
24 Mn3,4+ 25 Fe3+ 26 Co3+ 27 Ni 3+ 28 Cu2+ 29
CrChromic
Nickel ion
Cobaltic cobalt
23
Manganese ion
Ferric iron
Cupric copper
4+
4+
5+
2+
Rb+ 37 Sr 38 Y3+ 39 Zr 40 Nb 41 Mo 6+ 42
Molybdenum
Zirconium ion
Rubidium ion
Sulfur
S
as sulfite (SO
(Some electrons remain in outer shell)
sulfate (SO42– )
m=47.867
r=0.68 m=50.942 m=51.996
r=0.59
r=0.52
46 47 48
50 52 53 54
50 51
49 50
e.g., as vanadate
Nonmetals
Cations that
coordinate with O2– (± OH–) in solution
4+ 16
5+
6+
Intermediate Cations
14 P
15 SSulfur as 16
as silicate (SiO ) Phosphorus as
or Si(OH)04
6
C
H
Anions
Anions that commonly coordinate with H+
(e.g., as CH4, NH3, H2S, H2O, etc.)
4–
3–
2–
Gases
z/ =
r 16
6+
Sc 21 Ti 22 V 23 Cr 24
Vanadium ion Chromium, e.g. as
Scandium ion
Titanic titanium
m=40.078 m=44.956
r=0.81
r=0.99
39 40 41
36
Krypton
Rn
Aluminum ion as
Al3+ or Al(OH)3–n
n
Elements that are thought to make up most of the
Earth's core (Fe>Ni>Co), along with possibly S or O
r=0.77 r=0.71
z = 32 = ionic charge ÷
r
ionic radius
m=24.305
r=0.65 m=26.982 m=28.086 m=30.974 m=32.066
r=0.41
r=0.50
r=0.29
r=0.34
24 25 26
32 33 34 36
28 29 30
31
Fe 3+ 27
Fe 2+
5+
6+
3+
4+
2+ 20
m=22.990
r=0.95
m=39.098
r=1.33
36 38 40
Xe
Magnesium ion
Sodium ion
Potassium ion
m=39.948
r=1.8
Kr
Na+ 11 Mg2+12 Al 13 Si
(No ionization)
Intermediate
z
/r =
1
m=14.007
m=10.811
m=12.011
r=0.20
r=0.11
r=0.15
10 11
14 15
12 13 14
4+
5+
3+
Noble Gases
Anions with
which soft cations
preferentially
coordinate
10
9
2
bicarbonate (HCO3- ) as nitrate (NO3– )
& carbonate (CO32- )
Lu
2
67
3
Ions essential to the nutrition of at least some vertebrates
("essential minerals")
Li
z
/
r =
1
Neon
m=9.012
r=0.31
or B(OH)4– )
Micronutrient solutes on land
Macronutrient solutes on land
1
34
Ne
4 B Boron 5 C
N
7
6
Beryllium ion
Nitrogen
as borate (B(OH) Carbon, as CO ,
m=6.941
r=0.60
m=4.0026
r=1.2
z = ionic charge ÷
r
ionic radius
= ionic potential
or charge density
Zr
Elements that make natural mineral alloys with Fe
Elements that make natural mineral alloys with Cu
Elements that make natural mineral alloys with Os
Elements that make natural mineral alloys with Pt
Elements that make natural mineral alloys with Au
Anions that form minerals with Ag+
Anions that form minerals with Au+
Anions that form minerals with K+ and Na+
Anions that form minerals with Mg2+
Anions that form minerals with Al3+, Ti4+, and Zr4+
Anions that form minerals with Si4+
Solutes that can be limiting nutrients in the oceans
z
r/ =
+
2+
LiLithium
Be
3
ion
17th to 22nd most abundant
Most abundant solute in average river water (HCO 3–)
2nd to 8th most abundant solutes in average river water
z
/r =
2
z
/r =
1
2
Most abundant (bold)
Radioactive (italicized)
Radioactive
decay pathways
0
Helium
9th to 16th most abundant
β-
α
12 0
He
z
/ =4
z/ r =
r 2
Cations that coordinate with
O2– in solution (e.g., as
NO3–, PO43–, SO42–, etc.)
5+
Cations that
coordinate with OH–
or O2– in solution
4+
3+
234
EC, β+
(or elemental radius
for elemental forms)
Cations that form simple fluoride minerals
Cations that form simple oxide minerals
Cations that form simple sulfide minerals
Cations that form simple bromide or
iodide minerals
Cations that form oxysalt minerals
(e.g., S6+ in sulfates, As5+ in arsenates)
10 most abundant elements in Earth's crust
11th to 20th most abundant elements in Earth's crust
21st to 40th most abundant elements in Earth's crust
41st to 92nd most abundant elements in Earth's crust
Mg-Al-Fe-CaTi-rich minerals
See also Insets 1 to 6.
Ionic Radius (r) (Å)
0
(No ionization)
Naturally
occurring
isotopes
m=72.59
r=1.05
16
Noble Gases
Cations that
m=1.0079 coordinate
r=10-5 with OH– (or
H2O) in
123
solution
54
Ge
Actinium
Atomic Mass
Coordinate F>O>N=Cl>Br>I>S
Hydrogen ion
3+
Element Name
40
1
(number of protons)
Fe
Elements that occur as native minerals, recognized in antiquity
( recognized from Middle Ages to 1862;
recognized after 1963.)
Chromite
Forsterite
Anorthite
Augite
Enstatite
Hornblende
Ilmenite
Magnetite
Apatite
Titanite (sphene)
Zircon
Biotite
K-feldspars
Albite
Quartz
Inset 4: Solubility of oxide minerals of hard cations
+
Li4.4
*Order of crystallization in
any one magma depends on
bulk composition, pressure,
and fluid composition.
Melting T (K) of simple
oxides of hard cations
2+
3+
Be–7.4
B2.77
C 4+
N 5+
Bromellite
+
Na9.9
2+
Mg
Periclase
–2.4
+
K14.0 Ca2+
4+
Al3+ Si –3.9
–8.1
Corundum
Sc3+
+
Rb
28.9
2+
Sr4.3
Y 3+
5+
P–1.37
Ti 4+
5+
V –7.6
Cr 6+
Shcherbinaite
Zr 4+ Nb5+ Mo6+
Baddeleyite
Molybdite
2+
La 3+ Hf 4+ Ta 5+
Ba6.7
Mineral
–9.7
Log of activity of cation species
in distilled water at 25 °C
S 6+
Quartz
–9.7
Rutile
Lime 1.4
Si-Na-Krich minerals
(All electrons removed from outer shell)
(Thus a noble-gas-like configuration
of the outer shell)
Ions least depleted from mantle in formation of crust
Ions that enter early-forming phases in igneous rocks
Ions that enter later phases in igneous rocks because of
their large size (mostly "large-ion lithophiles")
8 most abundant solutes dissolved in seawater
Atomic Number
(see scale at far right)
z
/r
=
H+
"Hard" or "Type A" Cations
80
0
Cations that
coordinate with H2O
(or CO32– or SO42–)
in solution
Symbol
4 most abundant constituents
in atmosphere
th
5 to 8th most abundant
2
Outline solid for naturally occurring elements or ions;
dashed for ones that rarely or never occur in nature.
z
/
r =
Ions commonly concentrated in residual soils and residual
sediments. Small symbol ( ) indicates less certainty.
Ions concentrated in deep-sea ferromanganese nodules
Tantite
Th 5+
Thorianite
W 6+