Iridium jewelry

I have a client who is interested in having two rings made out of
pure iridium. I did some research on the internet, and only learned
of one jeweler who even makes iridium jewelry. Are any of you
familiar, and/or work with iridium as a jewelry metal? If so, here
are a few questions I have:

What are its working properties as far as hardness/flexibility? How
does it perform for stone setting? Can you laser weld on it? Would it
be possible for me to make a wax carving, and someone cast it for
me?

Any info is appreciated.
Thanks!
Diane

Hi Diane,

I have done a ring that was alloyed with platinum, but was mostly
irridium. The iridium came from a chemical supply company. I believe
it was Johnson Mathey. It was a powder. The casting turned out okay
but was kind of brittle. I cast it myself. I melted the pure
platinum, which was approximately 10 grams, first and preheated the
crucible and then poured in the iridium. I don’t know if this is a
very good idea. I believe the iridium costs more than the
platinum,but I"m not positive. The whole reason this was done was
that the man was a scientist and he had the materials on hand.
Otherwise, I don’t see much point to it.

Kevin

What are its working properties as far as hardness/flexibility? 

Extremely hard and not ductile at temperatures below 2000F

How does it perform for stone setting? 

Not by normal means

Can you laser weld on it? 

Yes

Would it be possible for me to make a wax carving, and someone cast
it for me? 

No, it is not cast, the melting temperature is way too high (4471 F)

From Wikipedia,

“Iridium’s modulus of elasticity is the second highest among the
metals, only being surpassed by osmium. This, together with a high
modulus of rigidity and a very low figure for Poisson’s ratio (the
relationship of longitudinal to lateral strain), indicate the high
degree of stiffness and resistance to deformation that have rendered
its fabrication into useful components a matter of great difficulty.
Despite these limitations and iridium’s high cost, a number of
applications have developed where mechanical strength is an
essential factor in some of the extremely severe conditions
encountered in modern technology.”

James Binnion
James Binnion Metal Arts

What are its working properties as far as hardness/flexibility?
How does it perform for stone setting? Can you laser weld on it?
Would it be possible for me to make a wax carving, and someone cast
it for me? 

Look it up on Wikipedia.

Very hard (mohs 6.5, harder than quartz, which is very hard for a
metal). Very brittle. Melts over 4400 F, roughly a thousand degrees
higher than platinum or steel. In short, you’re not likely to be able
to make a ring from it. Stone setting? Yeah, with glue. not with
moving the metal in any way. Not sure about laser welding. That might
actually work. But the stuff is very hard and brittle. Not normally
workable, so this is going to be a tough assignment. I rather doubt
you’ll find anyone who can cast it for you, as it’s melting point is
beyond what normal platinum type investment materials can handle.
Presumably you could sinter it, the process used in PMC products, at
temps somewhat lower than it’s melting point. This is how, for
example, tungsten light filiments are made (tungsten melts even
higher than iridium) Or a solid block could be carved, much as stone
is carved, with diamond or boron carbide tools. At around a thousand
dollars an ounce, it’s cheaper than platinum or pure gold, but a
solid block to machine into a ring will have a great deal of waste

However, change the plan to an alloy that contains iridium, and then
you’re very much in business. A platinum alloy with ten percent
iridium is one of the more popular and traditional platinum alloys,
with the iridium lending the platinum significantly increased
hardness and durability. That alloy can be hand worked or cast, and
is one of the best alloys for stone setting of any of the jewelry
metals. I’d strongly suggest you explain the working properties to
your client, and talk them into iridium platinum instead of trying to
obtain a pure iridium ring. It’s possible, likely even, that platinum
alloys could be custom made with higher percentages of iridium. How
much, before it becomes unworkable, I don’t know. By the way, the
color of pure iridium is somewhat straw colored. Pale yellow. Not the
normal white of most platinum group metals.

If your client is dead set on an iridium band, you might refer them
to this web site. They’re not jewelers, but a high tech materials
firm who saw a small market, and make a few styles of wedding bands.
Or you might contact them for help in making your custom job. If
anyone can do it, this would be the type of folks who might be able
to help.

Hope that helps
Peter Rowe