3 Pairs of Vintage GF Cameo Screw Back Earrings

Three pairs of vintage gold filled carved cameo screw back earrings. First pair are from the 1960s. Marked 12KT GF. Though the lettering is worn, I do believe these to be AMCO. Great condition. Some green tinting to GF. This is normal when there is a presence of copper. Size: 0.55 inchs x 0.5 inchs Second pair ate a lovely heart shaped cameo set in GF metal. There is no marking indicating what GF it is. There is also writing that is unclear to read. From what I can gather it's A D(?) O(?) R N A. Great condition for age. Age is unknown. Size: 0.6 inchs x 0.56 inchs Third pair are tge smallest of the lot. Marked 12GF 1/20 TOR. Great condition for age. Age is unknown. Some discoloring to gold fill. Could easily be cleaned. Size: 0.6 inchs x 0.5 inchs