These Mexican sterling screwback earrings are handmade in the 1940's by skilled Mexican craftsmen in Taxco mexico. I think that they look like a twisted ribbon. They say STERLING TAXCO with an assay mark for Sterling silver on the back, It is very interesting how they are made. When they put the screw onto the earring they put them on two different ways. If you look at the pictures carefully you can see that one is on backwards. They are still comfortable to wear, just a unique feature. They hang down 1 1/4". From my personal collection. You will love wearing these.