Over one million Pet Rocks were sold in 1975, makine Gary Dahl, of Los Gatos, California, a millionaire. He got the idea while joking with friends about his pet that was easy to take care of, which was a rock.

Research indicates that plants grow healthier when they are stroked.

Used in art the word "sfumato" refers to the subtle blending of an outline by gradually blending one tone into another.

AMAZING FACTS