The unique one-cent British Guiana magenta stamp, issued in 1856, sold at auction in 1970 for $280,000.
Notes on verification
Confirmed by Smithsonian National Postal Museum, Linn's Stamp News, and other philatelic sources. Core facts (1856 issue, uniqueness, 1970 sale price of $280,000) consistently corroborated; minor discrepancy over sale venue (auction house vs. private consortium) does not affect the claim's substance. [tier=silver indep_score=0.875 clusters=2 claim_tier=notable]
Sources
- Philately - Notable Stamps, Collections | Britannica (seed:culture_and_philosophy)
- https://postalmuseum.si.edu/exhibition/british-guiana-one-cent-magenta/timeline-of-a-rarity (corroboration)
- https://www.si.edu/newsdesk/releases/world-s-rarest-stamp-now-display-national-postal-museum (corroboration)
- https://www.linns.com/news/auctions/2014/june/unique-british-guiana-1-magenta-stamp-sells.html (corroboration)