What's Your Thoughts?

I came across this C19...only problem is it is not dull orange, but brown violet. My first thought was it came in contact with some chemical which caused the color change reaction.

Just curious what others my have come across

Read more at http://mystampworld.net/forum/#BzvIkBcKDkP4vV6I.99

Oxidation causes orange dies to change color to brownish shades. I have read of removing the oxidation by dampining a cotton ball with peroxide and enclosing that with the stamp in a small container. I think thats the method for a mint stamp.

Is this your stamp? Is this your scan? It's possible that a chemical change has occurred and there is a strong possibility that sulfuretting has happened. Sulferetting changes redish colors to a brownish color. You might try to remove the sulferetting in a hydrogen peroxide bath for a brief period of time. Search the U.S. classics forum here for "hydrogen peroxide" and you'll find recommendations for how to do so.

Oxidizing is the most likely. Especially if there was a source of sulfur near the stamp for a number of years. A very strong source of sulfur would be something made of rubber. Less likely but also possible is someone was having fun doing science experiments to see color changes in inks when certain chemicals are applied to old stamps.

Thanks Phil,
I took a cotton ball with Peroxide on it and placed it in a container with the stamp elevated and will see what happens.
I'll post the results if any after 24 hours .
Don

I'm very curious to know if the desulfuration can occur in the presence of high oxygen concentration (from the hydrogen peroxide) without the presence of water vapor. Can an oxygen tank produce the same results or is high humidity necessary?

Since it is a used stamp, the hydrogen peroxide can be applied directly to the face of the stamp without fear of damage.

Go to my website www.stampexpertizing.com, click onto "Articles" then scroll down to "How to remove oxidation from stamps".

Two comments on Bill's link:

1. I was not able to get it to work by just clicking on it while in the forum. I had to paste the highlighted words into my browser (IE11) to get there.

2. In his article Bill acknowledges that the problem is due to sulphur and that "oxidation" is a misnomer. But he admits that the misnomer is so widespread that you can't fight it. Maybe he could and should have put the word "oxidation" in quotes, but no one who knows the chemistry involved needs to avoid his article because of this title. He gets it.

Not so sure about his suggestions on how to apply the peroxide to gummed stamps or the use of an eraser, but we all have our favorite techniques.

if they're used as that one is I would just give it a bath in peroxide for a minute or two watching it of course to see what happens. Wasn't there a purple one issued with the same design?

The 5c had the same design and is violet. I can't find any variants of the 6c design AP8 in my standard Scott catalogue. C19 is the only listing and is "dull orange".

Thanks all for the information.

The stamp was placed in a plastic container elevated above one cotton ball I soaked and squeezed out any excess of peroxide. This morning (12 hours later ) the stamp had returned to the dull orange color and appears cleaner than before. The suggestion clearly worked without having to immerse in any bath but simply from the fumes and contact by the air in the container.
Thanks again!

Can you scan the stamp after the process? I'd like to see the change.

knuppster59, I'd also like to see the change. Until then, here is an earlier thread that discusses hydrogen peroxide use and photos of the results:
https://goscf.com/t/39040

Here's the same stamp after leaving in a container as noted above. Thanks again for all the useful information.

Essayk;

My bad. I stuck a comma in that link at the end so the it did not work. My apology. It is www.stampexpertizing.com That should work!