750, 585, and 417 Gold Markings on Jewelry
The chart shows that both 583 and 585 mean 14karat gold. You''ll see the same issue with 416/417 and 916/917 too. The USA allows gold jewelry to be under karat, slightly. In other words, it can be marked 10K when it''s only karats. So the higher number marking in these three cases means that it''s a higher quality gold, and not under karated.