"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
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
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.
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.)
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,
(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. "
(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.