The die clash is unusual in my experience. I've seen many Seated coins with a prominent clash mark in the right obverse field which corresponds to the lower edge of the eagle's right (facing) wing. I've never seen a clash mark like yours, which could be from Liberty's arm like TreasHunt suggests. Weird!
It certainly looks like the reverse die had extensive micro-pitting on the flat surfaces, causing the raised pimples on your coin. I don't see any equivalent marks on the devices. I guess rusting of the die is the most likely cause, although maybe ordinary wear and tear of the die could cause the same effect. The devices and edge features are pretty sharp which suggests the die was not extremely worn. In any case the pimples do not detract from the coin, as you point out.
Anyone else have any opinions about this effect?
It certainly looks like the reverse die had extensive micro-pitting on the flat surfaces, causing the raised pimples on your coin. I don't see any equivalent marks on the devices. I guess rusting of the die is the most likely cause, although maybe ordinary wear and tear of the die could cause the same effect. The devices and edge features are pretty sharp which suggests the die was not extremely worn. In any case the pimples do not detract from the coin, as you point out.
Anyone else have any opinions about this effect?






















