Beautifully engraved certificate from the Pet Rock Supply Company. The top of the certificate says "Society for prevention of Cruelty to pet Rocks". This certificate was for Rock Cross and Rock Slide Insurance. This historic document has an ornate border around it with the Director's name Dig M. Deep. In 1975, small round rocks were packaged in cardboard boxes, bedded with straw. A manual was included describing how to care for the rock. Certificates were printed to be issued to the Pet Rock Owners.