Israel does not require entry visas from most countries, including citizens with valid passports from the
For visitors from countries requiring visas: if you have established contact with a specific diamond company here, ask them to write to the Israeli consulate in your country to recommend you for a visa.
If you are not working with anyone yet, just write a letter to the Israel Diamond Controller with information about your company. The Controller will then write a letter of recommendation to the Israeli consulate in your country. You will receive an answer from the consul.