World’s rarest postage stamp put on show in Taiwan ‘British Guiana One-Cent Black on Magenta’ is world’s most valuable postage stamp Aug. 9, 2023 10:01# British Guiana One-Cent Black on Magenta# British Guiana# Guyana‘British Guiana One-Cent Black on Magenta’ is world’s most valuable postage stamp # British Guiana One-Cent Black on Magenta# British Guiana# Guyana
