His Gem cutting, 1955.

New York times, June 16, 2002: obituaries (John Sinkankas; mineralogist, gemologist, lapidary, author, and illustrator; b. May 15, 1915 in Paterson, N.J.; d. May 17, 2002 in San Diego)

Info. converted from 678, 2012-10-02 (b. 1915)