Object Identification can be tricky from a legal perspective, even if done informally.
Too many people expect Antiques Roadshow style observations or detailed analysis.
The Penn Museum limits its Object Identification information to "what an object might be and where it might come from culturally."
We never put anything in writing and if we do, it is couched in vague terms - "in the style of".
We work with the legal owner and photographs. We never review the objects in person.
And give a lot of referrals to appraisers / dealers these days.
As for Arrowheads - they are just plain difficult.
For the most part, they are generic in form and material.
And I've seen way too many rocks that are NOT arrowheads, which people dug out their gardens or picked up on a hike on the beach, woods, wherever.
Oh, and they actually teach flint knapping in experimental archaeology and in the boy scouts.
So, you really need to have a geographic locality as a starting point to begin.
I chaired a MAAM session on Object Identification ages ago, so I would love to hear if anyone out there is still providing this service.
Chrisso Boulis
Registrar Records
Penn Museum
T: 215-898-4088