Pet Rock Certificate Set (4 certificates) and Instruction Book - 1976. Includes 4 unissued certificates. 1. Pet Rock Pedigree Certificate, 2. Pet Rock Lifetime Stud Service, 3. Pet Rock Obedience Training Certificate, and 4. Rock Cross and Rock Slide Insurance. This set included an envelope and a Pet Rock Certification Package 18 Page Instruction Book. Pet Rock was a collectible toy made in 1975 by advertising executive Gary Dahl. Pet Rocks are smooth stones from Mexico's Rosarito Beach. They were marketed like live pets, in custom cardboard boxes, complete with straw and breathing holes. The fad lasted about six months, ending after a short increase in sales during the Christmas season of December 1975. Although by February 1976 they were discounted due to lower sales.
Certificate History from Wikipedia and OldCompany.com (old stock certificate research service)