Back to Ganoksin | FAQ | Contact

Purple gold of Tutankhamun


#1

Some Egyptian gold work of 1370-1080 BC has a shining rose-purple
patination, which so far from being the result of slow chemical
change over the centuries is an intentional effect. Example in
’Jewels of the Pharaohs’ by C.Aldred, plate 97.

One idea is that this colour has been achieved by introducing other
metallic salts into the metal at some stage of manufacture and it has
been suggested that iron pyrites could achieve this by forming a fine
film of iron oxide on the surface of the gold. Another suggestion has
been that a very thin film of enamel on the metal has picked up some
molecules of gold to give this colour.

See: Wood, R.W., ‘The Purple Gold of Tutankhamun’, Journal of
Egyptian Archaeology, London, 20 (1934, 62 ff.)

The Asian King of Mitanni, listing gifts that he was sending
Amenophis III, speaks of ornaments of gold ‘through which blood
shines’.

If any of your amazingly well-informed contributors can give me any
more on this ‘purple gold’, I would be eternally grateful.

David Kelsall (UK)


#2
If any of your amazingly well-informed contributors can give me any
 more on this 'purple gold', I would be eternally grateful. 

Can’t help you there. However, I did want to say thanks for the
really interesting references and I can’t wait to see where this
goes. You might want to post this message on one or more of the
historical newsgroups as well. One of my other passions is
homebrewing, particularly recreating historical recipes. The
historical brewing NG has been an excellent source of for
me, and I suspect you might have similar results for “period” jewelry
and techniques. Likewise with the myriad of SCA-related NGs.

Warm Regards,
Shawn


#3

Hi Shawn,

My dad was a nuclear metalurgist, and he experimented with lots of
esoteric alloys of gold and platinum, when they were looking at every
possible material in trying to come up with stable, less reactive
stuff to make sleeves and frameworks for uranium fuel rods.

Every so often he would show us really wild looking little pieces of
metal, that would go back immediately to his lab. I guess he wanted
something tangible, and unclassified, to show us what he did.
Anyway, he made a beautiful grey gold, and a purple gold…and they
were gold/aluminum, and gold/depleted uranium(not as radioactive).
Both of these (I believe) would be essentially unworkable as jewelry
alloys. There are even more colors possible if you get into "alloys"
that won’t ‘mix’, but must be made by combining superfine powders and
compressing them into a bar.

I think Steven Kretchmer, in NY State has investigated a lot of this
sort of thing. You might try contacting him. Hope this gives a little
help, anyway.

Lawrence


#4

Steve Kretchmer wrote an article for AJM in May, 1995 that reviewed
the basics of gold alloys, including various colors, as I recall. (A
Primer for Buying Gold Alloys.) There was also a profile of Kretchmer
published in September, 1994, that briefly discussed his colored
golds. (“The Color Purple” by Clark Heideger.)

You can order photocopies of these articles through the article index
on the AJM website at http://www.ajm-magazine.com.

Suzanne


#5

Modern American experience with purple gold is minimal. A very few
companies have done some work in purple gold, largely from Italy. The
stuff is problematic. G.I.A. had some colored gold information
published many years ago with Aluminum shown as the “purple” alloy. I
have a list in excel transposed from the old info, showing the use of
some very bad (toxic fume alert!) metals to get exotic color. One
problem is the aluminum ingredient. Aluminum requires a helium gas
cover to weld with aluminum, or it will ash as you melt, as shown by
"Heliarc" welding methods. Aluminum is very light compared to gold,
making it tough to mix. Finally, if you can get it to mix, then cast,
it has TERRIBLE working properties. It will not bend or roll out at
all. No setting either. It will not torch solder. It will not even
take a great polish. If anyone does get better results than what I
describe, I would be very surprised. In my opinion, the ONLY good
thing about this stuff is the stunning color. Steven Kretchmer has
done some purple work and in fairly high karat to boot. Whoever gets
this color to work may hold the info as VERY proprietary! He did one
beautiful demonstration/art piece for a show a few years ago. Daniel
Ballard


#6

Dear David,

I don’t recall having seen any response to your query about
Tutankhamun’s purple gold so I’ll have a stab at it. Purple gold can
be acheived by alloying .999 gold with aluminum…sorry, aluminium
to you Brits…I haven’t the foggiest as to what the proportions
might be nor would I know whether other alloy metals are used along
with it. Sounds like it might be a bit tricky to combine metals with
such disparate melt temperatures. Maybe John in Mapua can help.
Otherwise I would suggest your going to Oppi.I think that I will do
some experimenting along these lines. My customers are always looking
for a new gimmick.

As for achieving a purple patina on gold I am completely at a loss.
Obviously aluminium was not known in the mentioned era, but it is not
completely out of the question that something like bauxite clay or
cryolite might have been used to that effect.

Sorry I can’t be of more help, but maybe I have pointed in a
potentially useful direction. Ron at Mills Gem Co. Los Osos, CA.


#7

Dear Daniel, I really appreciate your insight into the purple gold
thread. I was on the verge of screwing up some .999 gold were it not
for your letter. I even have an order from a customer who was
enthused about putting some fine amethyst into purple gold. Maybe
I’ll be able to talk him into some corny old rose gold…Thanks again,
Ron at Mills Gem, Los Osos, CA


#8

Aluminum is probably not the material used in the pharaohs purple
gold. Aluminum is not found as a free metal in nature as it requires
electricity to refine aluminum from ore. It has only been around in a
metallic state for a little more than 100 years. So there must be
another alloy (doubtful) or it is a coating over the gold (most
likely) Also the aluminum gold system is not really workable as it is
an intermetallic mixture not a solid solution so it is very brittle.
It requires very special equipment to make it turn out as more than
an ugly mess in the bottom of the crucible.

Jim


@jbin
James Binnion Metal Arts
4701 San Leandro St #18
Oakland, CA 94601
510-533-5108


#9

Many thanks to Daniel, Ron and Suzanne for their As you
say, it is most unlikely that they would have used aluminium, not only
because of lack of a supply, but also because the ‘alloy’ is so
un-workable. The (smaller) gold ornaments that show this colour had
been subjected to considerable work in fashioning then into jewellery
items. R.W.Wood thought that it may have been due to a diffraction
effect on the surface of the gold items, or possibly to an iron
content. He reports that he alloyed fine gold with 1% iron into a
bead which, when hammered out into a disc and heated to a dull red
heat gave a purple colour matching ancient Egyptian articles almost
exactly. After dissolving the purple film with a mixture of HCl and
HNO3, microscopic examination of the surface showed a very marked
microcrystalling structure. He concluded that the Egyptian jewellery
had been heated after their manufacture - but surely the very heating
during their manufacture would produce the same result? I imagine
them using a charcoal brazier perhaps with the controlled addition of
air. Thanks again for the aluminium info, though. David Kelsall (UK)


#10
   Aluminum is probably not the material used in the pharaohs
purple gold. Aluminum is not found as a free metal in nature as it
requires electricity to refine aluminum from ore. It has only been
around in a metallic state for a little more than 100 years. 

Dear James Binnion

May I draw your attention to the fact that the Danish scientist H. C.
�rsted (Oersted) in the year of 1825 managed to produce the first
Aluminium from water free Aluminium cloride. First 50 - 60 years
later, however, the production of Al reached a level, where it could
be used for more normal purposes. First in 1886 Mr. Hall (American)
and Heroult (French) found out about the electrolysis process.

And by the way, … up until the Hall/Heroult invention Aluminium was
considered quite more costly than gold…

Just for the fun of it… and greetings from sunny, spingtime
Denmark, where the apples are blooming and the temperatures have
reached summer level.

Kind regards
Niels Lovschal, Jyllinge, Denmark
@L_F8vschal
phone (+45) 46 78 89 94