Mineral Value for Social Security

Need to find out value of a mineral right for Social security in order to get benefits started. I have to have something in writing to take to SS…have never dealt with this before…the right as follows Union Point Red Fork SE SE Sec 9-9n-9E Pottawatomie County I 40 acres x 1/4th x 1/5th = 2 net mineral acres. The document is affidavit filed 4/19/2018 book 2018. Page 4265. Original beneficiary Howard Leon Peyton. Any help is appreciated.