Help To ID US 1851 Series 3c Washington Stamp, Please

The color has me puzzled. I have seen purple mentioned in Scott. I have many others of this type but they all look more orange or brick colored. In person this looks brown or maybe purple to me. Help, please!

Scott #11

What color would you call it?

It is a #11A, re-cut inner frame lines. I don't think its the plum color. The stamp appears sulfurated/oxidized due to exposure to sunlight and/or chemicals causing a reaction of the ink pigments resulting in the color changing/darkening. Origonally, the color probably was much like the other 1851 3-cents stamps/covers you have. There is a variety of colors for that issue. You can reverse the change, at least to some degree, by using a solution of hydrogen peroxide and water. I've done it by lightly applying the solution with a Q-tip, let it stand a short period of time and then dabbing the solution off. You may have to repeat this more than once. When you stop getting any effect, then use plain water to cleanse the solution off the stamp. Take care in doing this. Others on this sight may suggest other methods to revive the color or may advise leaving it as it is.

Nice find Mike. Like Al said there are many colors associated with the 1851 and 1857 3 cent stamps. The 11-A in your photo is closest in color to either brownish carmine or possibly even (Are you sitting down?) the rare plum shade. The original violet purple pigment that produced the plum color was only used on a few plates and only for a very short time, so only a very few were actually ever produced. The pigment was especially susceptible to fairly quick oxidation which turned the original purplish color to brown and then to dark brown. So if your stamp is a fairly darkish brown, it might be wise to have it expertized and get a certificate issued for it. Good luck, and let us all know if you struck pay dirt!