It looks like a Guilford Round Base which is 6,200 - 5,000 years old. The material may be Rhyolite. I see that Pemberton, NJ is just on the outskirts of the northeastern distribution range so it may be another type. Some others will chime in I'll bet. Nice find.
I actually disagree with Guilford... I hunt Burlington County and find these somewhat non-descript ovoid points at two terminal archaic / woodland sites that I hunt. It's kind of hard to see in the photo if there's a stem or not... it doesn't look like it, hence my calling it ovoid, but if there is... it could be a poplar island point.