I want to search for lost precious metals and want to rent a geiger counter to enhance my search. I do not want to purchase, I want to rent.

Try tis:
Metal Detector Rental - Metal Detector Rentals.com is a South Carolina locally owned Metal Detector Rental company Myrtle Beach South Carolina.
I would try Pawn Shops and Yard Sales, even Ebay.
Owning is the way to go.

Do you mean a geiger counter ? To find radioactive material?
Or do you mean a commercial grade metal detector