Jonas Simon Okker, born 27 October 1862 and diamond polisher from Amsterdam, was a son of Simon Marcus Okker and Dina Grewel. He married 24 May 1893 in Amsterdam to Henriëtte Gobes, who was born 25 November 1869 in Amsterdam as daughter of Salomon Gobes and Grietje Content. In 1894, the couple had a son named Sigfried.
Jonas Okker was the youngest in a family with five children. His brothers, Aaro…