Datolite from Westfield, Massachusetts


Kraus, E.H.; Cook, C.W.

American Journal of Science 22: 21-28

1906


Kraus
and
Cook—Datolite
from
Westfield,
_Mass.
21
ART.
VI.-_Datolite
from
Westfield,
Massachusetts
;
by
E.
H.
EIRAus
and
C.
W.
COOK.
SEVERAL
months
since,
the
Mineralogical
Laboratory
of
the
University
of
Michigan
purchased
from
Ward's
Natural
Science
Establishment
of
Rochester,
N.
Y.,
an
excellent
suite
of
datolite
crystals
from
Westfield,
Mass.
At
that
time,
crystals
of
datolite
from
this
locality
had
not
been
described,
and
it
was
therefore
decided
to
carry
out
a
chemical
and
crystallographical
inTestigation
of
the
same.
Recently,
how-
ever,
Whitlock*
described
several
datolites
from
this
locality.
Whitlock
confined
himself
to
a
crystallographic
study
of
these
interesting
crystals,
and
since
our
investigations
not
only
cor-
roborate
many
of
his
observations,
but
also
give
some
additional
facts,
we
have
thought
it
wise
to
present
the
same
in
detail.
Crystallography.—The
original
purchase
consisted
of
six-
teen
crystals
varying
from
an
half
to
an
inch
and
an
half
in
diameter.
Subsequently
fifteen
others
were
added,
so
that
thirty-one
crystals
from
this
locality
are
now
in
the
possession
of
this
laboratory.
However,
through
the
kindness
of
Ward's
Natural
Science
Establishment,
all
of
the
material
in
their
possession
was
placed
at
our
disposal,
so
that,
in
all,
forty-seven
crystals
were
examined..
According
to
Mr.
R.
F.
Jones,
by
whom
the
crystals
were
collected,
the
datolite
occurs
in
the
cracks
and
crevices
of
Lane's
Trap
Quarry,
Westfield,
Mass.,
half
way
between
Springfield
and
Westfield.-
Most
of
the
specimens
seem
to
have
been
col-
lected
during
the
past
two
years.
All
the
crystals
are
exceed-
ingly
clear
and
transparent
and
of
such
sizes
as
to
make
accurate
goniometric
observations
possible.
Four
distinct
types
of
development
were
noted.
Even
though
datolite
has
from
time
to
time
been
studied
crystallographically,
there
is
still
considerable
difference
of
opinion
as
to
the
selection
of
the
a
and
c
axes.
Although
HessT
and
Schroeder
had
previously
shown
that
datolite
crys-
tallizes
in
the
monoclinic
system
instead
of
orthorhombic
as
assumed
by
Levy,
I1
Haiiy,11
and
Miller,
**
it
remained
for
Dauber-H-
to
positively
establish
the
fact.
The
elements
of
crystallization
obtained
by
Dauber
are
:
a
:
b
:c=1•26574
:1
:0'63446
13=90
°
9'.
In
so
doing
the
form
m
x
(fig.
1)
was
assumed
as
the
unit
*
N.
Y.
State
Museum,
Bull.
98.
19.
Compare
Whitlock,
N.
Y.
State
Museum,
Bull.
98,
19.
Pogg.
Annalen,
xciii,
380,
1854.
§Ibid.,
xciv,
235,
1855
;
also
xcviii,
34,
1856.
Q
Description
d'une
collection
de
mineraux,
etc.,
pp.
179
and
182,
1838.
"f
Dana,
System
of
Mineralogy,
6th
ed.,
1892,
505.
**
Mineralogy,
1852,
408.
Pogg.
Annalen,
ciii,
116,
1858.
22
Kraus
and
Cook—Datolite
from
Westfield,
_Mass.
prism.
Rammelsberg,*
in
establishing
the
isomorphism
be-
tween
datolite,
gadolinite,
and
euclase,
accepted
the
position
proposed
by
Dauber
but
made
g
(fig.
1)
the
unit
prism,
whereby
the
ratio
was
reduced
to
0•6329
:
1
:0
.
6345.
Groth,1-
Liweh4
Goldschmidt,
and
others
have
accepted
these
values.
Hintzell
accepts
the
statement
of
Liideckelf
that
this
position
is
the
more
natural
and
gives
the
simpler
indices.
Liidecke's
argument,
moreover,
loses
its
force
when
we
con-
1
Ii
sider
that
seventeen
of
the
thirty
new
forms
described
by
him
were
afterwards
shown
by
Goldschmidt**
to
belong
to
anglesite
and
not
to
datolite.
Dana,tt
however,
does
not
accept
the
above
position,
but
follows
Levytf
and
interchanges
the
a
and
c
axes.
In
so
doing
the
values
obtained
by
Dauber
are
taken,
so
that
the
ratio
adopted
by
Dana
is
:
a:
b
:
c=0
.
63446
:
1
:
1'26574.
We
agree
with
Dana
that
this
position
permits
of
a
more
natural
interpretation
of
the
crystals
and
also
affords
the
simpler
indices.
This
position
is,
therefore,
the
one
accepted
by
us.
As
indicated
by
Dana,
the
isomorphism
existing
between
datolite,
gadolinite,
and
enclase
can
be
shown
by
this
position
just
as
well
as
by
the
one
adopted
by
Rammelsberg.
The
four
types
of
development
already
referred
to
may
be
described
briefly
as
follows
:
Type
one
(fig.
1),
as
noted
by
Whitlock,
is
the
predomina-
ting
habit.
Thirty-four
crystals
were
found
to
possess
this
*Zeits.
,
3hr.
der
Deutsch.
Geol.
Ges.
xxi,
807.
f
Tabellarische
Uebersicht
der
Mineralien,
1898,
116.
Zeitschr.
fur
Krystallographie
u.
s.
w.,
vii,
569,
1883.
II
Index
der
Krystallformen
der
Mineralien,
1886,
I,
485.
Handbuch
der
Mineralogie,
II,
164.
Zeitschr.
fiir
Naturwissenschaft,
lxi,
235-404,
1888.
Zeitchr.
fur
Krystallographie,
xviii,
280,
1890.
ft
System
of
Mineralogy,
6th
edition,
1892,
504
and
505..
ft
Loc.
cit.
§
Loc.
cit.
Kraus
and
Cook—Datolite
from,
TiresVeld,
Mass.
23
development,
which
may
be
characterized
as
the
pyramidal
habit.
The
following
forms
were
observed
on
this
type
:
a{100},
b{010},c10011,/72p10kr12301,011201,/{130},x{102},
v
{IN},
u{104},
m
x
{on},
g
10121,
t
0131,
m
y
{067}
(new),
m
10.1.10t
(new),
n
{111},
g
11211,
Q
{122},
v{1:11},
b
{223},
€{1
-
12},
µ,{114},
K
{115
Hdi.1.10}
(new),
M{122},
ari241,7r{231
}
,
j1.48},
,u,
11.4.10}.
The
pinacoid
a
{010}
is
always
present
as
a
brilliant
face.
The
form
b{
010
}
occurs
on
about
fifty
per
cent
of
the
crys-
tals
of
this
type.
When
present,
it
appears
as
a
narrow
edge
giving
good
reflections.
e
{001
}
is
generally
very
small,
often
giving
no
image
whatever.
The
prism
9n1110}
is
usually
to
be
observed
as
a
thin
edge
and
is
always
present.
o{120},
which
is
frequently
present,
possesses
two
characteristic
outlines
(figs.
1
and
4).
In
some
instances
it
shows
natural
etching.
It
then
appears
as
a
very
dull
face
giving
poor
reflections.
/1
230}
(fig.
2)
was
noted
on
several
crystals,
giving
very
good
readings.
/{130}
was
observed
on
but
one
crystal,
beveling
the
edge
between
the
faces
v(11I)
and
m
x
(011).
2
3
m
m.
E
d
e
,.
,A.
The
negative
hemi-orthodome
x{102}
is
the
predominating
form
of
this
type
and
aids
materially
in
orientating
the
crystals.
The
faces
are
often
broken
and
the
surfaces
are
more
or
less
uneven,
and
hence
give
poor
reflections.
v{103}
and
111104}
were
observed
but
once
as
very
small,
narrow
edges.
Of
the
clino-domes
/n,
;
{
011},
g{012},
and
t{113}
are
always
present.
Of
these
forms,
m
x
1011}
is
always
large.
my{067}
(fig.
3)
and
/22,{0.1.10}
are
new
to
datolite.
Even
though
they
were
observed
on
only
two
crystals,
the
observed
and
calculated
angles,
nevertheless,
leave
no
doubt
as
to
their
identity.
:
M
y
=
(
067)
:
(067)
(0'11.0)
:
(WHO)
Observed.
Calculated.
94
°
39'
94
°
46'
14
38
14
25
Of
the
pyramids,
/1{111},
$1121
},
€1112},
µ{114}
are
generally
present,—v{
111
}
usually
predominating.
24
Kraus
and
Cook—Datolite
from
Westfield,
M488.
122
}
is
frequently
present,—often
as
a
dull
face
giving
no
reflection.
b{223},
sometimes
quite
large,
is
among
the
commonly
observed
forms.
AI3122},
i-123},
and
al124}
are
also
among
the
forms
fre-
quently
observed.
The
new
forms
e'0_48}
and
/1/11-4-10},
noted
first
by
Whitlock,
were
observed
on
several
crystals.
pl{1.4.10}
gave
very
good
readings,
but
e'
{148}
was
identified
by
zonal
relationship.
The
location
of
these
forms
is
shown
4
5
1--
-
-----t
9"
a.
a
E
V
E
fr
r
i,
fi
in
figure
2.
ri,11:1•10}
is
also
new
to
the
species.
This
form
may
be
considered
well
established,
as
shown
by
the
following
angles
Observed.
Calculated.
m
:
n
w
=
(110)
:
(I•1
10)
76
°
49'
76
°
52'
Type
two
(fig.
4)
also
possesses
a
pyramidal
habitus.
It
is
distinguished
from
type
one
chiefly
by
the
absence
of
the
basal
and
clino-pinacoids.
This
type
was
observed
seven
times,
pos-
sessing
the
following
forms
:
a{100},
x{102},
m,{011},
g{012},
m{110},
op20},
n{111},
b{223},
€11:12},
A{1.13},
The
pinacoid
al100}
occurs
as
a
small
triangular
face
giving
excellent
reflections.
As
in
type
one,
the
hemi-orthodome
x0_02}
is
the
predominating
form.
The
prisms
vd110;,
and
o{120}
are
always
present
though generally
small,—o1120
beveling
the
edge
between
the
faces
v(111)
.and
m
x
(011).
Of
the
pyramids,
61112
and
X1113}
present
large,
uneven
faces.
h
223
}
is
usually
dull.
The
other
pyramids
appear
as
very
small
faces.
Type
three
(fig.
5)
was
observed
on
four
crystals.
It
may
be
characterized
as
possessing
a
prismatic
habitus.
All
forms
are
well
developed,—the
following
being
noted
:
.a{1.00},
b
{010}
,
c
10011,
x
{102}
,
${1.02},
m
x
{011},
g1012i,
t{013},
27/
{
110},
9/
{
111},
E{i12},
Ar1131,
µ{114
j
.
The
pinacoid
a{100}
is
the
predominating
form,
the
others
being
quite
equally
developed.
All
faces
except
the
positive
_Kraus
and
Cook—Datolite
from
Westfield,
Mass.
25
hemi-pyramid
v{1
-
11
}
and
the
positive
hemi-orthodome
e
{1.02
}
are
brilliant,
giving
good
reflections.
v1111
appears
as
a
dull
face
in
each
instance.
el102
in
addition
to
being
dull
was
so
small
that
it
could
only
be
identified
by
zonal
relationship.
The
three
types
thus
far
considered
show
a
marked
resem-
blance
to
the
Bergen
Hill*
dalolites.
Type
three
also
simulates
crystals
from
Toggiana.t
Type
four
(fig.
6),
which
was
observed
on
two
well
developed
crystals,
possesses
a
tabular
habitus.
In
some
respects
it
resem-
6
C
V
7L
9
a
V
bles
datolite
crystals
from
the
Lake
Superior
region
described
by
Osann.t
The
following
forms
were
noted
:
al100},
b
{010},
{001},
290.10},
m
x
{oli
g{012},
t{013},
x{102},
v11031,
n{m},
0121.
As
may
be
seen
from
figure
6,
the
basal
pinacoid
el
001
}
is
especially
prominent
in
this
type.
Of
the
clinodomes,
91012
predominates,
—m,
011
t
and
ti
013
being
comparatively
nar-
row
faces.
The
orthodomes
x3102
t
and
v{103
are
both
dull
faces.
In
all
thirty-two
forms
were
observed.
They
are
as
follows
:
Pinacoids
a{100},
b{010},
c{001}.
Prisms
n{
100},
r{230},
o;120},
/1130;.
Clinodomes
171,
x
0.11}
g{012},
2121067},
t{013
}
,
md0•1•10}.
Orthodomes
102
f,
v{
-
103},
?t
.
104},
e_T[021.
Pyramids
22{111;-,
13{12
1
},
Q{122},
bP23},
E{112},W13},
µ1114b,
71,11'1'10},M{1
-
22}
,
i{1.23},
ar1241,7r{231},
E{148},
,
i
u,'{1•4•10}.
Of
these
m
9
{067},
m
z
{
0.1.10},
and
n,
1..1.10}
are
new
for
datolite.
On
account
of
the
excellence
of
the
various
faces,,the
observed
angles
agree
very
closely
with
the
calculated.
The
elements
E.
S.
Dana,
this
Journal
(3),
iv,
416,
1872.
f
Dana's
System
of
Mineralogy.
Zeitschr.
fur
Krystallographie,
xxiv,
543,
1895.
26
_Kraus
and
Cook—Datolite
from
Westfield,
Mass.
of
crystallization
for
these
crystals
differ
but
slightly
from
those
usually
accepted,
as
is
shown
by
the
following
:
Westfield
a
:
b
:
c
=
0'63482
:
1
:
1'26567
$
=
90
°
9'
Danat
a
:
b
:
c
=
0'63446
:
1
:
1.26574
13
=
90
°
8-1'
The
measurements
give
the
following
results
:
27/
:
M.
"'
=
(110)
:
(I
1.0)
M
x
:
a
x
=
(011)
:
(Oil)
a
:
c
=
(100)
:
(001)
1
:
l'
=
(130)
:
(130)
o
:
o
=
(120)
:
(120)
r
if
I
=
(230)
:
(2'i0)
r
:
M,
:
m'
=
(0110)
:
(0110)
t
:
t'
=
(013)
:
(013)
g
:
g
=
(012)
:
(012)
m
y
:
m
y
=
(067)
:
(O67)
a
:
m
x
.
=
(100)
:
(011)
a
:
n
=
(100)
:
(111)
a
:
/3
=
(100)
:
(121)
a
:
Q
=
(100)
:
(122)
a'
:
v
=
(Too)
:
(Ill)
a'
:
E
=
(100)
:
(112)
a'
:
A.
=
(100)
:
(113)
a'
;
p,
=
(100)
:
(114)
a'
:
k
=
(Too)
:
(115)
a
:
x
=
(100)
:
(102)
a'
:
M
=
(100)
:
(122)
c
:
v
=
(001)
:
(103)
c
:
a
=
(001)
:
(104)
2n
:
x
=
(100)
:
(102)
rn
:
n
=
(110)
:
(111)
a
:
v
=
(110)
:
(Ill)
rn'
:
b
=
(110)
:
(223)
277/
:
E
=.7
(110)
:
(112)
m'
:
A
=
(110)
-
:
(113)
m'
:
p,
=
(110)
:
(114)
rn'
:
n,
=
(110)
:
(1.•1•10)
m
:
p
=
010)
:
(121)
222
:
M
x
=
(110)
:
(011)
o
:
x
=
(120)
:
(102)
o
:
n
=
(120)
:
(111)
o
:
[3
=
(120)
:
(121)
o'
:
M
=
(120),
:
(122)
o'
:
u'
=
(120)
:
(123)
0'
:
a
=
(120)
:
(124)
o
:
rn
x
=
(120)
:
(011)
o
:
7r
=
(120)
:
(231)
o
:
7r
=
(230)
:
(
231)
g
:
p.
=
(012)
:
(114)
g
:
k
t
,
=
(012)
:
(1'4'10)
f
These
values
of
Dauber,
modified
as
indicated
on
page
22,
are
also
accepted
by
Groth,
Goldschmidt
and
others.
Observed.
=
64
°
49'
*
Calculated.
_
103
22
30"*
89
51
*
55
19
55
°
24'
30'
76
25
76
29
87
13
87
11
14
38
14
25
45
42
30
45
45
64
45
15
64
38
30
94
39
94
46
89
56
89
54
30
38
57
38
56
53
44
53
44
58
12
58
15
30
39
0
30
38
59
49
59
49 57
58
34
45
58
32
30
64
47
64
41
69
2
68
44
45
1
45
57
24
57
49
:33
36
33
35
26
35
26
29
53
21
53
15
22
57
30
22
54
22
58
30
22
57
32
28
45
32
35
40
19
40
13
51
56
51
49
59
20
59
15
76
49
76
52
25
41
25
38
65
9
65
7
30
63
59
64
3
29
40
29
38
17
14
17
7
30
31
45
31
43
42
50
42
32
51
1
51
5
51
57
51
57
13
13
13 13
10
9
10
15
29
16
29
13
11
17
11
19
_Kraus
and
Cook—Datolite
from
Westfield,
Kass.
27
Natural
etching
is
quite
common,
especially
on
the
pyramids
X
5
:1_13},
/..014}
and
K1T15}
as
noted
by
Whitlock.*
This
phenomenon
is
also
frequently
observed
on
the
prism
o1120}
and
the
pyramid
/31121
.
In
no
case,
however,
were
the
figures
of
sufficient
size
to
permit
an
accurate
determination
of
their
outline.
Chemical
Analysis.
For
the
chemical
analysis
one
of
the
clearest
crystals
weighing
about
ten
grams
was
selected.
It
was
perfectly
transparent
and
free
from
all
inclusions.
Concerning
the
methods
which
were
employed,
it
should
be
stated
that
the
boron
trioxide
was
determined
by
the
Gooch'
method.
Water
was
estimated
as
loss
on
ignition.
The
other
determinations
were
made
according
to
the
methods
recom-
mended
by
Hillebrand.t
Two
analysis
were
made,
which
show
very
close
agreement.
The
results
are
:
I
SiO
2
;
__.___._______37'60%
Fep
s
•10
A1
2
0
3
14
Ca0
34.64
Mg0
'32
B4O
3
2
1
*76
H
2
O
5'67
Total
1000230
II
Average
37'58%
37'59%
.10
10
16
15
34'74
34'69
'31
'315
21.94
21
.
85
5'76
5'715
100.59%
100.41%
The
average
of
the
above
analyses
agrees
very
closely
with
that
required
for
the
accepted
formula
EICaBSiO
r
.
This
was
to
be
expected
because
of
the
unusual
clearness
and
purity
of
the
crystals.
It
is
also
to
be
noted
that
this
analysis
is
very
similar
to
Bodewig's§
of
the
datolite
from
Bergen
Hill,
N.
J.,
as
is
shown
by
the
following
comparison
:
Theoretical
Westfield
Bergen
Hill
SiO
2
3
7
•6
3
37'59
37'48
Fe„0
3
_
_
_.
.10
.
12
A1
2
0
3
15
Ca0
34
.
95
34'69
35
.
42
MgO
_ _ _
.
'31
B
2
0
3
21
.
81
.
21
.
85
21'14
H
2
O
5°61
5'72
5°7
1
Total
_
_ _ _
_ _
_
_
_
100'00
100'41
99'87
N.
Y.
State
Museum,
Bull.
98,
12.
f
F.
A.
Gooch,
Am.
Chem.
Jour.,
ix,
23,
1887.
F.
A.
Gooch
and
L.
C.
Jones,
this
Journal,
vii,
34,
1899.
Bulletins
148
and
176
U.
S.
Geol.
Survey.
§
C.
Bodewig,
Zeitschr.
fiir
Krys.,
viii,
211,
1884.
28
Kraus
and
Coole—Datolite
from
Westfield,
Mass.
This
similarity
in
the
composition
of
the
datolites
from
these
two
localities
becomes
more
pronounced
when
we
consider
that
the
value
given
by
Bodewig
for
boron
trioxide
is
the
mean
of
three
determinations,
one
of
which
is
21.6
per
cent.
This
agrees
very
closely
with
the
values
obtained
by
us.
Specific
Gravity.
For
the
determination
of
the
specific
gravity
four
clear
crystals
of
convenient
size
were
used.
The'
determinations
were
made
by
means
of
the
hydrostatic
balance
at
a
room
temperature
of
19.5°
C.,
the
water
being
21.5°
C.,
with
the
following
results
3'0005
2'9
9
9
8
3'00
6
5
3'0
1
6
5
Average
3'005
8
The
values
for
the
specific
gravity
are
usually
given
in
the
various
standard
text-books*
as
varying
from
2.9
to
3.
Bauer,t
however,
gives
2.9-3
.
6.
We
have
been
unable
to
find
any
records
whatever
of
datolites
possessing
a
specific
gravity
as
high
as
3.6,
and
on
account
of
the
fact
that
the
figures
obtained
by
us
on
very
pure
material
are
much
lower,
we
would
question
the
correctness
of
the
larger
value
given
by
Bauer.
In
conclusion,
we
wish
to
express
our
indebtedness
to
Prof.
E.
D.
Campbell,
Director
of
the
Chemical
Laboratory
of
this
University,
for
advice
and
suggestions
relating
to
the
chemical
portion
of
this
paper.
Mineralogical
Laboratory,
University
of
Michigan,
Ann
Arbor,
Mich.
March
30,
1906.
*
Dana,
System
of
Mineralogy,
1892,
504
Hintze,
Handbuch
der
Mineral-
ogie,
II,
167
'
Miers,
Mineralogy,
1902,
588
Naumann-Zirkel,
Elemente
der
Mineralogie,
14te'
Auflage
1901,
629.
f
Bauer,
Lehrbuch
der
Mineralogie,
2te
Auftage,
1904,
762.