It sounds like something issued privately as a so-called collectible. SD may refer to South Dakota or - ???
In any case, plated coins are rarely worth much more than face value because there's almost no secondary market where you can resell them.
My guess would be that it was plated with gold (or a gold-colored metal) after minting, and that it is thus worth about a penny.
I have a nickel that is a color of a penny I have a nickel how much is it worth
i have a penny ,the back is stamped ,the front is slightly stamped like an outline of the face , maybe 2 numbers ,very hard to see
Modified coins have no collector value.
1¢ It's either plated or has been exposed to a chemical that changed its color. That's a frequent experiment in high school chemistry.
The state was stamped on it after it left the mint. It has no collector value -- novelty value is perhaps 25 cents.
U.S. pennies have never been made out of silver. On a 1994-D penny, the silver-colored metal below the copper coating is zinc, NOT silver. It's worth one cent.
1 cent. It's plated. The US has never made a gold penny.
A new penny blank planchet is worth $1.50.
One cent. It was probably plated for use in jewelry or similar. It has no special value to collectors, however.
All 1935 US cents were struck in bronze. Any silver-colored cents with that date are either plated or have been damaged chemically, either of which would reduce their value to 1 cent only.
Its value is based only on the value of the metals it contains. A plated coin has no true numismatic value.