Very nice find and pretty material, but it sorta hides the flaking. Could you take a picture with the light at an angle that highlights the flaking for us? One from the edge might tell us something too. And as Niffler asked, is there any basal grinding?
Any chance the state archeologist is versed in ancient stone tools? The one we had was an expert in paleo tools. Sometimes you get lucky. What ever it is like 1320 said said it is an exceptional example.