Don't know. Possibly an old dip and naturally retoned unevenly, but I could not rule out the possibility of an improper wash of the planchet prior to the strike. Things were rough in San Francisco in 1906.
Numismatist. 54 year member ANA. Former ANA Senior Authenticator. Winner of four ANA Heath Literary Awards; three Wayte and Olga Raymond Literary Awards; Numismatist of the Year Award 2009, and ANA Lifetime Achievement Award 2020. Author of "The Enigmatic Lincoln Cents of 1922," Available now from Whitman or Amazon.
I've been wondering the same thing.
Often the yellow shows up around the edge creating a spotlight appearance.
Sometimes it covers part of the coin like the shadow of a cloud.
I don't have many gold US coins, mostly type pieces and a smattering of half eagles of both types. I do not understand why anyone would dip an originally toned gold coin. Seems insanity to me!
Comments
Don't know. Possibly an old dip and naturally retoned unevenly, but I could not rule out the possibility of an improper wash of the planchet prior to the strike. Things were rough in San Francisco in 1906.
Looks like a highlighter. I don’t think it is, but it sure looks like it.
I've been wondering the same thing.


Often the yellow shows up around the edge creating a spotlight appearance.
Sometimes it covers part of the coin like the shadow of a cloud.
My Saint Set
I saw that somewhere. I thought it was my eyes cause I was tired
A siege by the white prongs has induced a reaction! 😉
"She comes out of the sun in a silk dress,
running like a water color in the rain...."
Improperly neutralized dip residue. Cheers, RickO
I don't have many gold US coins, mostly type pieces and a smattering of half eagles of both types. I do not understand why anyone would dip an originally toned gold coin. Seems insanity to me!
Wayne
www.waynedriskillminiatures.com