I think the diamonds are set on knife-edged bars. Nothing "second-rank" about it and very fashionable between 1900 and 1920. Think of a Belle Époque evening gown and the typical late 19th century diamond collet necklace would have looked rather clumsy and old fashioned compared to these examples on S.J. Phillips' website:
--Previous Message-- : Thanks to Tamara for the close up. Now I see : that the earrings and the pendant look : relatively contemporary in design. I wonder : about the rivière: there are empty spaces : between the diamonds, that makes it an eh... : relatively second-rank diamond rivière, I : think? :