Comments:
Tarnished gold cases
It's not uncommon to see a vintage piece have some tarnish, as shown below.
I'm not sure what to make of this. None of my watches exhibit this. Most are worn with some regularity. Some sit for years (I hate to admit it but true).
Is tarnishing an indication of anything meaningful? Apparently, it can be removed quite easily. Yet this is not done prior to photography or sale. Is it seen as a patina that is desirable, as in rare coins? Maybe tarnish is used as an indicator that the watch hasn't been handled or used for a long period of time, which increases it value?
Here's some info that I found that gave a comprehensive description of tarnish and gold:
Good point ...
Even considering that I'm not a gold person, I already took pictures of gold watches with this issue.
Your point #3 is very important and not only to gold cases. I have a picture of an ex white dialed watch that got contaminated by the red dye of the watch case.
I go to post pictures of the two cases, as soon I arrive at my office.
Cheers
Nilo
Pics ...
Sorry, not a Patek but they illustrate my previous post:
1) First case: I believe that this is a box contamination:
2) Weird effect caused by a red box where the watch was located:
Cheers, Nilo
2) Weird effect caused by a red box where the watch was located:
Cheers, Nilo
There is a reason for this.
The reason this is occurring is because the case isn't solid gold. It looks to be heavily plated gold on steel. My guess would be that there was a flaw in the plating or abrasion of the finish allowing water and oxygen to attack the steel. This produced a reaction that blistered the plating underneath as can be seen on the right-hand side of the picture. A larger picture would be helpful, though.
Chlorine is my other guess.
One picture is not all that helpful, but please check if it stamped 18KT or 750? If it is not, it could be plated. The only other explanation I can think of is this is a form of chlorine corrosion that is attacking the alloy. It looks like a chemical reaction as a clear copper line can be seen. Has the original poster been handling bleach? A drop of bleach will destroy most gold alloys.
If it is a 2497 and it is a chlorine reaction, you're going to have to send it back to Patek to be re-cased as that is an expensive timepiece and the damage done to the case could have affected the gasket under the crystal, as well.
As a warning to everyone: Take off all gold alloys when using bleach, wear gloves or wash all jewelry thoroughly if it does come in contact with harsh chemicals.
If it is a 2497 and it is a chlorine reaction, you're going to have to send it back to Patek to be re-cased as that is an expensive timepiece and the damage done to the case could have affected the gasket under the crystal, as well.
As a warning to everyone: Take off all gold alloys when using bleach, wear gloves or wash all jewelry thoroughly if it does come in contact with harsh chemicals.
Thank you Andren
For the info to all about Karat gold (gold alloys) and their reaction to bleach/chlorine.
Yes, I too feel the image posted by the OP looks to be of a 'plated' watch, unless it has had direct bleach or so contact. Otherwise, it's hard to image what caused the 'blistering' (Towards the right side).
Please allow me to clarify several points
The reason that I have not provided more detailed photos are:
- The watch is not mine nor in my possession ... yet. 
- The watch is lot #366 in an upcoming auction. I'm hesitant to be referencing this lot in any more detail or reposting pictures for fear that I may upset either auction house or the moderators of this forum. I'm not sure of the rules so I was trying show just enough of the watch to make my point. I'm giving more specific information not to promote the watch but as a means for people to see the full pictures.
- I didn't mean to focus the discussion on this one particular watch. This sort of tarnishing is not that unusual in vintage Pateks. I was using this watch as an example of the tarnishing phenomena.
I'm still of the belief that the tarnish is easily removed, based on what I have read. Yet, the big auction houses (or the owners of these tarnished watches) do not make any effort to clean or prepare the watch for sale. I find this odd as the tarnish clearly distracts from the overall appearance. I would guess that most people's first reaction to the watch would be "what is wrong with the case". So I concluded that either I'm a dolt that doesn't appreciate the patina of vintage watches (much like a novice coin collector would clean their coins), or there is some sort of marketing strategy going on here.
Thurmond
I always assumed,
that tarnishing means not 18 carat gold and I am suspicious when I see a vintage piece tarnished: means fake to me. Although some pieces that look legit can be tarnished around the crown from time to time. Some cheap watch boxes from China can be made of fabric or plastic that tarnishes metals, so beware.
Really informative post.
Best,
Stan
Don't bid on it
This is potentially a six figure watch.
This condition is unacceptable. Don't buy it.
For the amount of vintage watches I've seen, this is not common whatsoever.
This condition is unacceptable. Don't buy it.
For the amount of vintage watches I've seen, this is not common whatsoever.