Switzerland 1850 Rayon II 10 Rp (yellow/black/red, no frame around cross; Scott 8 / Zumstein 16 II , SG 10) on folded letter to Schwyz, 18 June 1851 afternoon, (indicated by reverse “Z” datestamp), tied by the Zurich ‘Rosette’ (black Swiss cross within ornamental quatrefoil). On the back are two circular postmarks—one in blue ink and a faint second strike. 

Estimated value (uncertified): single used stamp $50–85 USD; cover with Rosette cancel $400–600 USD.