I have 7 Indian Head pennies.
6 of them weigh 3.1g. and one weighs 2.4g.
Did some of these pennies get minted on dime planchet?
Or some other type of minting error?
1st - I noticed this was your very first post - so, Welcome Aboard nf2002! You didn't list your state (or country) in your profile. So, you might consider jumping over to Sub-Forums: Select Your Area.... and selecting location information (i.e., clubs, hunts, finds, legends, maps, etc.) directly related to your state (or country). You might also consider adding your state (or country) to your displayed profile (SETTINGS -> EDIT PROFILE) so if you ask a question, etc. - people may have more success helping you (if necessary)...
Are all the details sharp and clear? It may have lost weight due to environmental damage, acid or extreme wear. Cents have mistakenly been struck on dime planchets but the coin would be silver instead of copper. Post pictures if you can.