Rock
From a geologists point of view it's just flint.
From an artifact collectors point of view there are many types of flint. And not all of them are flint.
On my semi-smart phone now, so don't have bookmark list handy, one site was something like lithicsourcesdotcom. Should be able to find on google. It had a pretty nice list of types of lithic material by state, some with pictures.
Archeologists might call it skunk flint but a geologist would just call it black and white flint.
I think in general that the correct name is the one used in the locality where you live.