 , cut diamonds constituted 23.2% of Israel's total exports and they were the country's biggest export product, amounting to 12% of the world's production.What was to become the Israeli diamond industry began in 1937, eleven years before the State of Israel was established, when the first diamond polishing plant was opened in Petah Tikva by refugee experts from the Netherlands.In 1938 the 15% import duty on imported rough stones was removed.