Piqued by Chris's success, I spent an hour in my best cornfield looking for arrowheads. Spring before the plowing is a good time to look since the soil is maximally washed down. So I spotted something of a good material:Looked closer and started to hope there was more beneath the surface: Here we go:Back home, after rinsing it: The material is a dark rhyolite. There are sources both east and west of here in Concord, and I do not know them well enough to say where the material came from. It reminds me of what I found two years ago [see here].