My mother was recently contacted by an independent contractor working for an Oil Company in regards to leasing her mineral rights on a 1/4 acre lot in Ohio. Here is the back story… her grandmothers sister never had kids, and sold her land but not the mineral rights. The Oil contractor is now starting to contact the heirs to pay them a very small amount of money to purchase the mineral rights. I’m finding out some extraction was done and stopped when they found out the landowners didn’t own the mineral rights. How do I find out what this mineral right might be worth? The mineral rights would split by 16 equal parties.