This pin is (both) Spanish and Italian. Made in Italy, for Spain. It was made during the 1936-1939 Spanish Civil War and issued to the Italian submarine sailors, who sailed with the Nationalists. No stone was added, because Italy did not operate under Spanish requirements. The actual pin made for the Spanish Nationalists, was different, in that it showed the port aspect, the crown was lowered down to the hull and the 'Legionnaires' symbol, was centered behind the conning tower. You can find further information about this pin, and many others, on the Submarine Insignia Collectors page, on Facebook.