Hopewell culture arrowhead
Anybody living in the US who comes across an object like this will immediately be able to tell what it is. The person who came across it knew it was an arrowhead, but they wanted to know more details about this ancient artifact. It could have been a prop used in a children’s play for all the OP knew.
Someone on Reddit told the OP that the arrowhead belonged to the Hopewell Indian culture, which dates back 2,000 years. The Hopewell tradition exited in the northeast and mid-west of the US during the Middle Woodland age. There’s no news whether the arrowhead is worth anything, but the OP could probably donate it to a local museum.