A handshake symbol on a tombstone usually signifies a welcome into the heavenly world. Sometimes you may see this as a symbol of matrimony on the grave marker of a married couple. If it’s a marriage symbol you may notice that one cuff will look masculine and the other, feminine.
Photograph: from the tombstone of Hugh L. Mitchell, died Dec. 14, 1882, age 34/4/17, Ute Cemetery, Aspen, Colorado.