"There
is no iridium in the iridium", Kurt Montgomery said to
me as we looked over the print out from the EDAX. We were
looking at the material analysis of a Waterman's Green #7
nib tip from the 1930's.
Most pens
today (and in the past) use an alloy of materials for the
hard surface tipping on the end of the nib. This alloy is
composed of a number of elements. If iridium is present at
all, it is rarely the predominate element.
The word
iridium has become synonymous with tipping, in much the same
way that Kleenex is synonymous with tissue paper. We all know
what we mean when we say iridium. It is the little bit of
hard white metal that is attached to the gold points of a
fountain pen.
My first
inkling of the relative absence of iridium occurred in 1991
when I took in a piece of tipping from a 1918 Waterman's N.Y.
Ideal #2 nib to the Pacific Spectrographic Laboratory in Los
Angeles for analysis. I got to watch as they put my pinhead
sized piece of metal in a ten-foot long machine. Using a burst
of energy, they vaporized the sample, turning in into a tiny
cloud inside a chamber. They then read a spectrum of light
as it passed through the gasses. The results* were:
Iridium
- 54%,
Osmium
- 44%,
Silver
- 0.70%, (these three last very small parts of the alloy were
probably contamination from the gold nib or the solder used
to fuse the tip to the gold.
Copper
- 0.50%,
Gold -
0.24%,
with possible
traces of Ruthenium.
I have
learned, by examining the margin between the tipping and the
gold of the nib, that all early points, those made before
the 1940's were made by attaching rough chunks of unshaped
tipping to the end of the nib. I could see a rough margin
between the materials, which indicated the crudeness of the
material that was placed on the end. This margin can be seen
using a 10-power loupe. In the early days of nib making, the
material used was unrefined ore, crushed to size and applied
onto the tip of the un-slit nib. It is for this reason that
there was a fair amount of difference in the tipping material,
depending on where on the earth it came from.
Melting
and alloying tipping material posed insurmountable problems
for the earliest pen makers. For this reason, many of the
earlier tips exhibit flaws that can be seen running from one
side of the points through to the opposite tine tip. A fine
uniform material was just not available.
An analysis
of naturally occurring iridium ore shows iridium in the presence
of osmium and ruthenium. (1)
One very
prominent theory has it that these materials are from asteroids
that have fallen to earth. The iridium that was present on
the earth, when the earth was formed, had dropped to the molten
center, leaving very little iridium on the surface. [(This
hypothesis explains the death of the dinosaurs and most vegetation
of the time as a catastrophic occurrence, the impact of a
huge asteroid off the Yucatan Peninsula, on the East coast
of Mexico, during the Cretaceous Tertiary (nicknamed the K-T
event.)] As the theory goes, not only did this event kick
up so much dust and debris that it blotted out the sun for
years, but it also deposited a thin layer of soil all around
the globe with higher than expected iridium content. This
soil layer has been found in Italy and other distant places
on the globe. (2)
Last year,
while making electron microscope photos of contemporary Parker
Duofold nibs with Kurt Montgomery, he explained that a material
analysis was also possible with EDS, energy dispersive spectroscopy.
By directing a beam of electrons at the metal, the composition
of the material could be analyzed.
The earliest
Parker nib tipping that we looked at was a Lucky curve (lazy
"S") from the mid-teens. Its analysis* shows similarities
to that of the first one that I analyzed, the Waterman's from
about the same period, except that this time there was more
osmium than iridium:
Osmium
- 44.3%
Iridium
- 34.8%
Ruthenium
- 20%
We looked
at a 1920's Parker Duofold Sr. and found that the material
was from different metal groups, a sure indication of an engineered
alloy. Notice that when the iridium disappears, the tungsten
shows up. This tip still shows the rough margins indicative
of fractured tipping material, not the uniform pellets that
came in during the next decade.
Osmium-
85.3%
Platinum
- 5.9%
Tungsten
- 4.51%
Ruthenium
- 2.01%
Copper
- 1.84%
A second
1920's Duofold revealed the following different engineered
tipping composition. Tantalum is very resistant to acid attack,
so it could be in there to hold up against the ink.:
Rhodium
- 43.6%
Ruthenium
- 19.3%
Gold -
17.4%
Osmium
- 6.9%
Tantalum
- 6.8%
Copper
- 5.3%
Iron -
0.7%
(It is
possible that in this sample, the machine read some of the
gold nib material, which showed up as gold and copper.) But
even so, when factoring this out, the other materials still
had a very different composition from the other Duofold that
we looked at. Where was the iridium? Parker Duofold nibs of
the 1920's were the gold standard of fine tips. I draw two
conclusions from this analysis: Parker was still experimenting
with their alloy, and iridium was not a necessary ingredient.
We can
date the senior Duofold size Lucky Curve nib fairly accurately
to the period when Parker first came out with the Jade Plastic
pen around 1924. Its composition shows no iridium at all:
Osmium
- 96.6%
Rhodium
- 3.4%
A later
Duofold pen, with the "Made in USA" imprint from
around 1929 shows a very different makeup. We are back to
the platinum group of metals characteristic of earlier "as
found" material tips:
Osmium
- 38.4%
Iridium
- 32.3%
Ruthenium
- 29.0%
A #4 New
York Waterman's tipping, ca. 1920 is similar to the Parker
Lucky Curve pen of a time almost ten years later. This is
more of the naturally occurring "iridium":
Osmium
- 34.6%
Ruthenium
- 33.4%
Iridium
- 30.0%
Iron -
2.0%
A Parker
Vacumatic from the late 30's shows the first major appearance
of tungsten along with cobalt. Here again Parker is engineering
different alloys.
Ruthenium
- 32.3%
Osmium
- 29.6%
Tungsten
- 20.1%
Cobalt
- 18.1%
A 1940's
Duofold shows a heavy reliance on tungsten. Because it does
not occur in nature with the Platinum group this is a designed
material tip (3):
Osmium
- 58.2%
Tungsten
- 41.8%
Tipping
on the Parker 51 with its nib marked RU is applied as a pellet.
Because pelletized metal do not occurs in nature, we can surmise
that this was refined, alloyed, and turned into a form that
could easily be used in manufacturing. (An awareness of osmium
as a dangerous biologically reactive substance occurred around
this time and may explain its absence. Osmium oxides
toxicity was well documented by 1940.)
Ruthenium
- 96.2%
Iridium
- 3.8%
We already
saw Waterman's material from the teens and 20's and how similar
it was to that used by Parker. Now in the 30's a similar pattern
of material usage emerged.
A Waterman's
#7 Green nib from around the mid 1930's looks like an intentionally
designed alloy:
Osmium
- 70.4%
Tungsten
- 13.6%
Platinum
- 10.3%
Aluminum
- 4.0%
Nickel
- 1.7%
A Conklin
from the 1930's with a crescent breather hole looks to be,
with its mix of metal types, a crafted alloy as well:
Osmium
- 47.9%
Ruthenium
- 33.9%
Tungsten
- 16.0%
Iron -
2.6%
Nickel
- 1.6%
Sheaffer's
nib tipping, from as far back as we could find samples, presented
the greatest number of components; a total of seven in the
early, circa 1919 Sheaffer's self-filling #4. Tungsten, though
neither precious nor noble, is very hard and durable. Sheaffer's
company, based on our findings, was the first to engineer
their tipping alloy:
Tungsten
- 45.6%
Nickel
- 33.4%
Iridium
- 7.7%
Osmium
- 4.7%
Iron -
4.6%
Silver
- 4.5%
Aluminum
- 2.5%
The large
Sheaffer's Lifetime from the mid 1920's shows a very different
profile:
Rhodium
- 55.0%
Osmium
- 31.8%
Ruthenium
- 8.2%
Platinum
- 3.0%
Aluminum
- 1.7%
Iron -
.3%
The Sheaffer's
Feather-Touch from the late 1930's with both tungsten and
cobalt is most similar to the Parker Vacumatic from around
the same period:
Ruthenium
- 37.1%
Osmium
- 30.2%
Tungsten
- 22.2%
Cobalt
- 8.2%
Aluminum
- 2.0%
Iron -
.5%
The presence
of aluminum, iron and copper, I believe, may be looked at
as a sign that the metallurgists were not entirely in control
of the materials that they were putting into the alloys. These
materials are either not hard, easily corrode, or both. The
other materials in these alloys are workable tipping materials.
Or possibly, Sheaffer's was experimenting with small amounts
of these elements to some end that I do not understand. Sheaffer's
company was well ahead of their time in many of their products
and processes. (Consider the early use of plastics and the
perfection of the lever filler.)
Conclusion
I am certain
that tipping was used in some sort of raw form on the earliest
nibs. I have come to believe that sometime around the late
teens, metallurgists were able to refine the ores and alloy
them into more desirable and/or less expensive metals. It
seems that a great deal of experimentation was going on during
this period in order to find a superior material. And finally,
the modern era of tipping emerged with the pelletized tipping,
which I have first seen on the Parker 51. All gold nibs made
today use regular spherical forms to provide the wearing hard
surface. A future article will look into the materials of
contemporary tipping. (Of the few that I have looked at so
far, none contain iridium)
*Please
note that because of averaging, or because only the elements
that we were looking for, show up, the numbers often do not
add up to 100%.
(1) Iridosmine
(or iridosmium or osmiridium) is a naturally occurring alloy.
It contains
osmium, iridium and smaller amounts of Pt, Ru, and Rh.
The ratios
in references are quite varied, one is 17-48% Os, 48% Ir,
and
Pt, Ru
and Rh (ca. 1974). Others current sources list it at up to
80% Os
and up
to 77% Ir. A 1932 Russian technical paper (where the pen tips
were probably
from)
states osmium contents between 30 and 65 weight %.
O. E.
Zvyagintsev, Z. Krist., 83, 1932, 172-186
(2) "In
1980 Alverez, Alverez, Asaro, and Michel, reported their discovery
that
the peculiar
sedimentary clay layer that was laid down at the time of the
extinction
showed an enourmous amount of iridium. First seen in the layer
near Gubbio,
Italy, the same enhancement was seen worldwide in a 1 cm layer
both on
land and at sea. The Alverez team suggested that the enhancement
was the
product of a huge asteroid impact.
"On
Earth most of the iridium and a number of other rare elements
such as
platinum,
osmium, ruthenium, rhodium, and palladium are believed to
have
been carried
down into Earth's core, along with much of the iron, when
Earth
was largely
molten. Primitive "chondritic" meteorites (and presumably
their
asteroidial
parents) still have the primordial solar system abundances
of
these
elements. A chondritic asteroid 10 km (6 mi.) in diameter
would
contain
enough iridium to account for the worldwide clay layer enhancement.
This enhancement
appears to hold for the other elements mentioned as well.
"
http://spacelink.nasa.gov/Instructional.Materials/Curriculum.Support/Space.S
cience/Stars.Galaxies.and.Amazing.Phenomena/Comet.Shoemaker-Levy9/Background
.Material
http://spacelink.nasa.gov/Instructional.M
oemaker-Levy9/Comet.Fact.Sheets/K-T.event
(3) "The
Platinum Metals and Their Alloys" by R. F. Vines,
The International
Nickel Company, Inc, 1941, NY, NY. Kurt Montgomery pointed
this reference out to me. He said, "This is an interesting
reference since it is contemporary with some of the nibs analyzed.
In the 1941chapter on iridium, there is no mention of using
pure iridium as a pen tipping material, either currently or
previously." (pg. 43-45.)
Many thanks
to Kurt Montgomery, without whose help this article would
not have been possible.
©
1998 John Mottishaw No reproduction or distribution without
permission. first
published in The
PENnant Vol. XIII, No. 2
|