1851 6kr yellow, the so-called Yellow Mercury, clear "Klagenfurth" cancel, cut in diagonally at left, showing portion of adjoining stamp at right, incredibly strong and natural color, with Mercury quite visible, fresh example of this difficult stamp, with 2007 Ferchenbauer certificate, cat. $10000 (Cat No. P2) (Image)

Cat. $10000, Est.US$1,000