Slider. A
TPG would wimp out and AU58 it. I believe it Mint State. The fields are actually quite impressive - this coin is not far from the original strikes. Even still has original mint wash under the chin.
Which is a cool thing, because it is plainly an EDS of VAM-1B, the most recognizable 1921-D
VAM. Yours has only the very first of the die cracks, from the looks of it.
http://www.vamworld.com/1921-D+VAM-1B1It's a "Gateway
VAM," one both extremely popular and rather common so it tends to drag people into VAMming. It's available throughout the stages of die state - people actually collect it by die state. As such, it'd probably carry a bit of a premium - nothing huge - if sold attributed.