Napier screw back earrings gold tone diagonal Ribbed shrimp screw hinge clip on

Vintage Napier screw back earrings gold tone shrimp style screw hinge clip on. Vintage Napier screw back earrings gold tone diagonal Ribbed shrimp style earrings . They flip open like a clip on style and then screw down to tighten on the ear: screw hinge clip on. Very pretty classic design . Dime and ruler in pics above to help with size visualization, Questions are always welcome. Has NAPIER stamped on the back in large block letters with copyright symbol, Patent number also looks like 3.178.475 on the hammer part .. a bit difficult to make out but that is my best interpretation on the number I can make out with my old eyes. They weigh 6 grams on my kitchen scale.