Hi
I once saw some chains at a supplier what he claimed was made out of
black gold I would not believe him though but now I have a customer
asking me to add some black gold rap on his bracelet does any one
know if black gold exists and if so where I could find some I would
need 24 gauge wire If not black gold can anyone suggest what other
material I could use that would not tarnish or rust eventually
Thanks
Gary
does any one know if black gold exists and if so where I could find some
I have never made any, but I have a recipe for black gold, which is:
14K Black Gold - 58.5% Gold, 41.5% Iron
Good luck!
Matthew Crawford
www.MatthewDesigns.com
There was a previous thread about Black Gold on Orchid. Someone
cited The Argen Corporation as a manufacturer. I contacted them
asking for more about the alloy and they sent me this:
The Argen Corporation
Alloy Specification Sheet
18 KT BLACK GOLD
COMPOSITION
Gold Cobalt
75.0 25.0
PHYSICAL PROPERTIES
Melting Range 996-1185 C
Casting Temperature 1285 C
INSTRUCTIONS FOR USE
INVESTING: A high-heat (phosphate-bonded) investment may be used
or an investment for Platinum. Follow the manufacturer's
instructions.
FLASK TEMP: 800-850 C
CASTING: 1285 C casting temperature. Must be done under a
protective atmosphere.
DEGASSING: Heat in air to 900 C. Hold for ten (10) minutes. Cool
in air. Surface will develop a black oxide. Polish using normal
procedures.
The alloy is for casting only, not fabrication, if I remember
correctly. In other words, I don’t think you can solder it.
Beth
I remember this being worn to great effect at one of the recent
Oscars by at least one movie star. It looked amazing and rea.lly set
off the stones that she was wearing.
There are several “Black” golds being sold right now. The are all a
coating or oxide layer on the surface of the gold. Some like the
cobalt-gold and iron-gold alloys are an oxide that are formed in a
post finishing heat treating step others like the Rado line are CVD
coatings on the gold and others are a form of electroplating. In each
case the bulk metal is not black the color is just a surface coating
that will scratch off over time.
Jim
James Binnion
@James_Binnion
James Binnion Metal Arts
360-756-6550
Black gold does exist. Boucheron used to makes some spectacular pieces using it. I asked my teacher about it when I was still in school and he told me it was made from a gold/iron mix and it was EXTREMELY fragile.
Like “blue” gold, black gold is not an intrinsically black alloy.
It’s greyish white. But it can be given a nice black patina. Argen
metals carries an 18K alloys they sell as “black gold”. Coloring it is
a heat treatment. Hot enough, by the way, that stones other than
diamond probably would not survive. Their “black gold” is a nice gold
color, so is probably not based on just iron.
The gold iron alloy is not what I’d call “fragile”. it’s just quite
brittle. Rolling it or drawing it has to be done gingerly. But can
still be done. For “fragile”, try purple gold, an aluminum/gold alloy.
That’s so brittle and glass-like that dropping a piece can shatter
it. Unlike black or blue colors, is an intrinsically purple alloy,
not a surface patina.
peter
DEGASSING: Heat in air to 900 C. Hold for ten (10) minutes. Cool in air. Surface will develop a black oxide. Polish using normal procedures.
Their instructions are a bit unclear here. Polish BEFORE the heat
treatment, not after, as polishing would cut through the black oxide.
The alloy is for casting only, not fabrication, if I remember correctly. In other words, I don't think you can solder it.
You can fabricate it just fine, at least in terms of it’s
workability. The main problem is that solders won’t develop the same
black oxide. We tried it a bit with laser welded seams, though, and
that worked, using argon shield gas for welding. The main problem for
us was the need to heat treat for the color. Made it impractical to
set stones and then heat treat…
Peter
If not black gold, maybe try a patina'd titanium?
Niobium is reported to heat-patina to a rich black color.
Lee
If not black gold, maybe try a patina'd titanium?
If someone knows a way to make titanium turn black (short of
painting it), I’d sure like to know!
Noel
mathew, the alloy of 14 parts fine gold and 10 parts iron will make a
rather dingy whitish mess, but when warmed slightly, it does indeed
turn black. I’ve done a bit of casting with it but had limited
success rolling it out. have fun.
tom arnold
If not black gold, maybe try a patina’d titanium?
If someone knows a way to make titanium turn black (short of painting it), I'd sure like to know!
Satin finish, etch, or sandblast the surface if it’s not already a
dull surface. Clean well. then heat red hot with a somewhat oxidizing
flame. Let air cool. I think that works, unless I’m remembering
seeing that with niobium, but I’m pretty sure it was titanium.
Peter
I think there are ductility issues with gold-cobalt alloys which
make them difficult to fabricate (roll, draw, etc), so they probably
are only suitable for casting. However, they can be soldered,
although the solder will not match the black color of the gold.
Michael
Niobium is reported to heat-patina to a rich black color
I have torched niobium to a black patina. A flaky, white substance
will develop on the surface during the heating, and under it is the
black oxide. I heat it to a medium-bright orange color and hold it
there for a minute or so. It is not only a nice, deep black, but also
very durable, requiring at times a light filing to get through if it
is to be removed. The surface can be sanded and polished and still
retain the black finish in many cases. I have observed that the black
oxide is also harder than the niobium I started with.
Matthew Crawford
www.MatthewDesigns.com
Satin finish, etch, or sandblast the surface if it's not already a dull surface. Clean well. then heat red hot with a somewhat oxidizing flame. Let air cool.
I’m pretty sure that would get you a medium gray, but I’ll give it a
try. What I really need is a black I can put in specific, controlled
areas, but any black is a start. Thanks!
Noel
While we’re on a thread that involves a lot of use of the word
“patina,” something that has a patina has been patinated.
“Patinate” is the verb form; “patina” is a noun.
I’ve seen dozens of instances of the non-word “patinaed” on jewelry
websites and in magazines, and it makes my teeth itch. Anybody ever
see that episode where the Animaniacs attempt to pronounce “aeiou”?
Cheers,
Jessee Smith (Fogey at Heart)
www.silverspotstudio.com
Cincinnati, OH
What I really need is a black I can put in specific, controlled
areas, but any black is a start.
If you get this figured out, I’d love to know about it. I’ve used
shakudo (oxidized) in some pieces, with varying results.
Matthew Crawford
www.MatthewDesigns.com
I've seen dozens of instances of the non-word "patinaed" on jewelry websites and in magazines, and it makes my teeth itch. Anybody ever see that episode where the Animaniacs attempt to pronounce "aeiou"?
It has been a trend for many years, the unrestrained verbing of our
nouns. Greened amethyst would be another example. We didn’t make it
green, we “greened” it. Rather than asking about my typing skills, a
recent job interviewer asked about my “keyboarding.”
The verbing of nouns is a trend for which I have little enthusiasm.
Lee