First year of issue for both the Proof Shield Nickel Series and for the change of the 5 cent denomination from silver to nickel (both continue together until 1873). Extremely low mintage of 600 coins of which most were saved, making this issue scarce yet very accessible. Scarce in all grades and becoming rare as a high-end gem. Difficult to locate with cameo surfaces and a true rarity with deep cameo surfaces, as only a handful exist. Nice toners can be found with some searching.