Discoloration in 22 kt yellow Gold

Jewelry Discussion
1

Dear All,

At present, we are receiving frequent complaint from the customers
that the metal is getting discoloured.

This defects are happening frequently in 22 kt chains.

It is turning brownish colour over a period of usuage.

Can u all suggest reasons for the defects and ways to prevent the
same.

Regds

Uma Maheswari.C
QUALITY ASSURANCE
04344 - 554741
@Uma_Maheswari

2

Are you absolutely sure your chains are 22K? If you are getting
frequent complaints, I don’t think it is. Perhaps it is only plated
wire instead of 22K. A simple test will tell for sure.

-k

Karen Christians
M E T A L W E R X
50 Guinan St.
Waltham, MA 02451
Ph. 781/891-3854 Fax 3857
http://www.metalwerx.com/
Jewelry/Metalarts School & Cooperative Studio

3

There is a brief mention of this at

it is not very helpful. Dr. Christopher Corti spoke about this at one
of the Santa Fe Symposiums you might try to contact him through the
World Gold Council.

Jim

James Binnion
@James_Binnion
James Binnion Metal Arts

360-756-6550

4

hello Uma,

acording to my belief one of the prime reason for the discolouration
is due to sweat and atmospheric conditions. as for solutions there
should be a transperant protective layer which will prevent sweat
and atmospheric conditions reacting with the mettle. currently such a
layer is applied over finished silver jewellery, utencyls etc. also a
more thicker version (electrophoretic lacqer) is used for immitation
jewellery (six month guranty type) due to which the jewellery becomes
scratch proof and chemical reactions proof.as for gold i have not
come across any such process as yet. we are in the lookout for such a
process as we cater to many retailers who are also facing similar
problems, i will let you know as soon as some break through is
achieved, hopefully soon.

thanks,
Hitesh Satikunver
Tanvi Arts (jewellery surface decorators)
Mumbai,
56059454, 9323231311

5

Hi Jim

http://www.ganoksin.com/borisat/nenam/wgc-gold-karat-tarnish.htm

I read the paper you referred to and got to think. Aggressive
environment with a hint of food and spices. Somewhere in the back of
my mind there’s something saying that the active substance that
makes you cry when slicing/cutting onions has something to do with
sulphur. Does this ring a bell with anyone else? And if my stomach
remembers correctly onion is an important ingredient in Indian
cooking. In the onion is a substance that might permeate through the
skin, maybe more easily so in a hot climate.

michaela, now off to the kitchen

6 
there's something saying that the active substance that makes you
cry when slicing/cutting onions has something to do with sulphur.

You bet. Onions burn your eyes by releasing sulfur compounds which
interact with the moisture of mucous membranes to form sulphuric
acid. The mellow, “sweet” onions such as vidalias and walla-wallas
are grown in sulphur-poor soil, hence their lack of pungency.

Lee

7

hello Uma,

you can know more about your perticular problem as well as about
electrophoretic laquer from :

company: m/s. R.R.Chemicals (Mumbai) owner: Mr. Rao (who is respected
for his thorough knowledge and who has given many lectures at
seminars of electroplating & surface finishing)

company contect person: Mr. sunil Patil (who has hands on knowledge
of electrophoretic laquer) cell no: 9869049317

thanks,
Hitesh Satikunver