Bloomed gold

A few years ago, while in an antiques shop I saw a peice that the
owner of the shop said was bloomed gold. It was worn but you could
still see some of the effect. I wasn’t all that impressed due to the
worn state of the peice I saw. Now I have a client who wants the look
of bloomed gold. I really have no idea what unworn bloomed gold
should look like and I’m not sure what it is really. My assumption
was that it was a heavy type of surface alloy depletion; however,
another antique dealer who is more of a jeweler said she didn’t think
it was that at all.

I checked Oppi and Brephol, but found nothing. It could be listed
under some other term than bloomed gold, but I don’t know what that
term would be.

Any ideas as to where to get some I didn’t find
anything of note from an online search.


I checked Oppi and Brephol, but found nothing. It could be listed
under some other term than bloomed gold, but I don't know what that
term would be. 

This sound like the result you get from “bombing” with cyanide. I
used to work at a place that did that.

Don’t do it. It’s not worth it.



Bloomed gold is alloy deletion leaving a pure gold surface on a
piece. This is a different look than gold plating a piece since a
piece with alloy depletion leaves a nice frosted effect.

Greg DeMark

Is it like the 24kt gold and platinum cufflinks we did years ago


I found something online that describes bloomed gold as an acid etch
that leaves a slight matte, textured surface. Now that I read that I
realize I’ve seen that on hundreds of old pieces, didn’t know it had
a special name.

Maybe you could experiment with some aqua regia. Maybe aqua regia on
top of a glass bead blast finish, may not be authentic but might

I don’t know if its the same stuff, but I have seen a lot of old
pieces that had a slightly dull brownish gold finish(like gold paint)
but when heated or polished revealed a decidedly pink gold base. If
it is the same stuff maybe the acid attacks the copper at a higher

Food for thought.

Have fun.

If the term gold blooming is giving the surface a 24 ct colour, as
others on Orchid have suggested, then here is a formula for what I
called gold colouring. Back in the mid 1960s we used this process
when we wanted a variation of gold colours on the 18ct gold UK Field
Marshal’s batons we made. Each baton had a conical mount at each end,
decorated with chased wires and at one end a model of George and the
dragon. We used the method of boiling a chemical mixture in a
crucible. The chemical mixture was 40% Potassium Nitrate (or salt
peter) 20% Alum, 20% common salt and 20% water. The gold piece was
secured to the end of a copper wire and dipped into the boiling
mixture for a few minutes at a time, the piece was washed with hot
soapy water after each dipping, and would be repeatedly dipped until
the required 24ct colour was achieved, incorrect timing would
discolour the piece. These chemicals dissolved the lower metal alloys
from the 18ct, leaving a 24 ct surface that could be scratch brushed.
Then the chased parts of the baton cones were masked and the bare
surface metal polished back to the 18ct colour which left a good
colour contrast between the chased section and the bright polished
surfaces. Beware if you try this method, that the fumes are toxic and
the process must be done in a free air environment or safe fumes
cabinet. In later years I would colour the Field Marshal baton cones
by the means of masking and then I would use the skills of a good
gilder to obtain the colour difference, which was better for my
health in the long run as I used to do my chemical colouring in an
open fireplace hoping that the fumes went up the chimney.

Peace and good health to all
James Miller FIPG

under some other term than bloomed gold, but I don't know what that
term would be. 

I think I remember reading that this is a technique of raising gold
content just on the surface of, say, a 14K item by immersing it in
acid so that the other metals are eaten away, leaving a very
"golden" top layer of purer gold.

But now I can’t find that reference…


You don’t need to use aqua regia to get this surface. Being that aqua
regia is so so dangerous; the off gassing can burn your lungs before
you know it.

USE iodine. Go to the pharmacy and buy pure iodine. I don’t know if
it is really pure but it is not the little bottle that you buy for
cuts. Ask your pharmicist about the safety hazards. We ordered it by
the gallon for about $40.

Here is what you do, and be sure to have ventilation on full blast.
It is not as dangeous as Agua regia but don’t take chances with your
lungs and eyes.

1 Have the piece finished, no knicks scratches etc.

  1. Clean piece.

3 heat up a beaker of the iodine about one inch deep should be
enough, on a hot plate to about 160 + degrees.

4 put in piece strung on a wire of 14 carat or other gold wire that
you have around.

5 experiment as to how you want to leave it in, try 30 seconds and
then longer,to start until you like the look.I am sorry but I can’t
remember how long we did leave it in for the really storng look. We
did this a couple of years ago.

6 rinse in sink under water.

7 use a little soap and water just to be sure all of the iodine is

8 Viola’ you have gold crystals.

The structure on the crystal growth on the piece is dependant on what
the stucture was when cast. You will get different results as to size
of structure everytime a piece is cast. There is some liturature that
states that you can increase the gold crystal size by heating the
finished piece in a kiln for several hours at a relatively low temp.
It is all in the archive, you can look it up. However, I never had
any luck when I tried it.

This look can be very striking but it is somewhat ephemeral. It can
scratch easily and kind of wear away. If you leave it in the iodine a
long time you can get pretty deep into the gold. and then it is
pretty permament. we had a couple of pieces that had really deep [.1
maybe.2mm deep etch] that were amazing.

It doesn’t have to have that dull kind of dusty look either. We
experiemented with pin tumbling and all sorts of polishing
techniques to brighten up the surface.

You can do it to lower carat golds but you end up with the dull ,kind
of corroded surface. Sometime people do it to 14 and 18 carat gold to
make it look really old.

Good luck, D

My memory of this is that is has come up on Orchid before and the
discussion lies in the archives.

here are some notes from the thread

Making the crystals large by slow cooling/heating might help. Bruce
Holgrain speaks of elecrostripping salts. I have a vague memory of
using warm nitric acid (That is a fume hood/chemical lab procedure


I found this when I googled: BLOOMED GOLD: karat gold which has been
treated with nitric acid, causing the alloy to dissipate from the
surface, leaving a thin matte surface layer of pure gold (has a
“frosted” appearance)


If you etch with nitric acid you will get the effect you describe.
The acid dissolves the copper and silver on the surface and leaves
the fine gold standing slightly proud. The Romans utilised the
technique for debasing their coinage without making it look obvious.
the motor industry [amongst others] uses a similar technique for
porous catalytic converters.



You can gold plate with a matte finish in 14k, 18k, 22k and 24k. I
have it done all the time. I don’t like the shiny plating so I
always get the 18k or better, plating in heavy gold with a matte
finish. It looks like something from antiquity, has a really pretty


I’ve typically used Nitric to dissolve previous lead repairs on karat
gold items. I’ve never experienced any kind of etching on the gold
itself. The gold seemed unaffected. I don’t recall the exact nitric
concentration but it was up there, as it fumed. And room temperature.
Maybe in days gone by a hot acid bath might have been the ticket for
blooming (conjecture on my part here, I did find a reference to
nitric for blooming which puzzles me as it seemingly contradicts my
experience) but I’d be REAL reluctant to monkey around with that.

I did find a reference to nitric for blooming which puzzles me as
it seemingly contradicts my experience) but I'd be REAL reluctant
to monkey around with that. 

Yes please don’t monkey around with nitric acid it is very
dangerous. I gass myself once and I was using it outside. My lungs
hurt like hell. coughe all sorts of gunk and lost my voice for a
while. try the iodine. D


I found a jeweler who does bloomed gold and though the shop manager
wouldn’t tell me much, I gleaned enough from them to verify that
James had the answer I was looking for. After reading James’ post I
realized that the process is one that I’m not interested in pursuing
myself. I’m concerned that after spending much time and effort making
a complex peice that I’d screw it up beyond repair on the last (or
second to the last) step. Plus, as James points out it sounds quite
dangerous if you don’t have the proper equipment. So I’ve asked the
jeweler who does bloomed gold to process my piece for me when I get
to that step.

Thanks everyone who posted suggestions. Orchid comes through again.


I've typically used Nitric to dissolve previous lead repairs on
karat gold items. I've never experienced any kind of etching on the
gold itself. The gold seemed unaffected. 

Your findings agree with the fact that aqua regia is used to etch
gold. Nitric on its own doesn’t work. It needs both the nitric and
hydrochloric acids to etch gold.


If you use nitric acid you need to be wearing the proper respirator,
properly fitted, and in a properly vented (hood ventilator) area.

Beth Wicker
Three Cats and a Dog Design Studio

But now I can’t find that reference…Would it be Russian Gold
Plating. You can also Google Mariam Haskell