Note the streak marks on the field surface.....Is this some kind of error and if so, any guesses what it would be called?
They're called Die Polishing Lines. If a die is polished to harshly it will leave scratches on the surface. When a coin is struck with those dies the metal from the planchet (coin blank) will fill those recessed scratches on the die, creating raised lines on the surface of the coin. This is a somewhat common occurrence and doesn't command a premium.
