Middle Eastern Yämän (Yemen) - Hadhramaut Silver Choker Necklace

These necklaces really confuse me as I am not sure where they are actually from or who actually makes them. They're commonly known as Hadhramaut necklaces, named for the Hädrämäwt (Hadhramaut) geographic region of Yämän (Yemen). However, I've also heard people describe similar necklaces as having been made in äl-Cäwf (al-Jawf) and Märib (Marib). 

This necklace has been restrung, but with all its original components (except for whatever mechanism was used to actually tie it). Silver, red glass, and what may be coral or possible sherpa coral. 

It is dated to the early 20th century 

This item is located in our American depot, which ships from the U.S.A.