This necklace features a 1969 6c United States stamp called "Plant For More Beautiful Parks" from the beautification of America series.
These stamps publicized First Lady Ladybird Johnson’s personal program for the Beautification of America. Its goal was to encourage Americans to take pride in their country and plant flowers and trees.
The image was taken from a real, used, vintage postage stamp and may have post office cancellation marks.
The size of the pendant is 20mm and the chain is 18 inches long, in a matching antique bronze finish with a lobster clasp.
Pendants are water resistant but not waterproof, I recommend removing before showering, bathing or swimming.