Chocolate brown gold

I have heard some claim this but no one seems to sell it or have any
to show. So I sure would like to know where one would buy some.

Jim

Brown: 18k Pure gold-75%; palladium-18.75%; silver-6.25% 

That is Pd white gold not brown

James Binnion

I mentioned a while back that someone had asked me about chocolate
gold - a customer brought in a picture and said “I want that
color”… At the time, I said I didn’t know, and I’ve noticed that
everybody here has just said, “It’s a plating process or
something…” So the detective comes out… Just my own curiosity and
knowlege - not looking to start a plant.

One problem is that the internet is vast, but it’s not THAT vast.
There’s much that just isn’t there, or requires things like Gopher
and Archie, which I’m familiar with but, hey, that’s a bit much.
Plus I doubt it would be there, anyway. Basically, I just thought
I’d pass on what I’ve found - not a whole lot, but more than I knew
before.

Chocolate gold is formed by physical vapor deposition of rose gold,
the general process of which is here:
http://www.pvdcoatings.net/About_PVD_Coating/about_pvd_coating.html

That’s related to chemical vapor depositon and others. Look up “Thin
Films” if you want to explore that. That’s the same process that
makes gold “color” watches, cufflinks and the like. Which is
zirconium nitride or something similar - there are a couple of them.

In that effort, I found the following sentence about black gold that
was interesting and intriguing: Plasma assisted chemical vapour
deposition process involving amorphous carbon, and controlled
oxidation of carat gold containing chromium or cobalt.

Or from another source: Amorphouse carbon is also used at times, with
the Plasma Assisted Chemical Vapour Deposition process. Controlled
oxidation of carat gold containing chromium or cobalt can also be
made to yield black gold.

And another page - note the reference to the Santa Fe Symposium:
http://utilisegold.com/jewellery_technology/colours/special_colours/

All of the sources I’ve found are saying the same things, which
either makes it true or it means they’re all quoting each other ;<}

But it seems that those are the processes… Neither PVD or CVD
isn’t something most anybody here would contemplate setting up in
their shop (+$100k), so it’s really either an outsource situation or
a fake-it-somehow-else situation…

http://www.donivanandmaggiora.com

Just like a dog with a bone ;}

Real interesting paper, based on the Santa Fe Symposium paper:

http://tinyurl.com/cqwo6u

Don’t be alloying with beryllium, chromium, cobalt and others unless
you understand everything about them - you could kill yourself.

For Jim Binnion or anybody else interested:

http://tinyurl.com/cntk4a

Not exactly on topic, but immensely useful nonetheless:

http://tinyurl.com/cpree6

Also available in Word format…

And just happened on this one, much here, too:

http://tinyurl.com/aw4uyl

Well, that should keep everybody occupied for a good long while ----
enjoy!!!