Welcome to CT. The 1968-D is common by any measure and can still found in your pocket change in very nice condition. I can't tell if yours is uncirculated or the look is just the result of very old and worn dies. My gut tells me that it is a combination of light circulation and worn dies. They are really only worth significant money in very high grades with nice strikes and full detail. However, you have a bit of toning developing and someone may pay a few bucks for it on eBay.
