Vintage signed sterling and amethyst Mexican artist made mod choker. Signed and marked with the Mexican mark of the eagle which was retired around 1979. The piece most likely dates to around the late 50s early 1960s per the mod clamper choker style and the Iguala mark- a town seen on some pieces that are a bit earlier. Full signature is 925 Iguala, Mexico, MSA, Eagle 2. Beautiful design on the neck and comfortable fit. Los Ballesteros created a necklace that is signed with the classic B, which I have seen before, that is an almost exact match in terms of choker construction, the amethyst and spring design, however this only has a MSA- could be Miguel Alonzo who was also a smith for Los Ballesteros. One thing is for certain, it is a quality piece of Mexican sterling work from a desirable pre 1980s time period. About 16″ around with a natural .45″ gap, flexibility. The amethyst and silver design on each end is about 1.5″ long.