Vintage Gold Étranger Stamped Hoop Earrings

Gold Étranger stamped vintage earrings. I’m not sure what karat gold these are, but the ET stamp implies that they are under 18k and were imported into France between 1864-1893. There is some green discoloration on the clasp hinges which is not noticeable when worn, but this indicates that these earrings are probably a low karat gold.