Hi Paula thanks for writing in. There isn't one specific country - I've seen a large Moroccan silver bracelet stamped 850 to a small George Jenson pin (valued at around $1,000 US) stamped 850 (see image below)
It doesn't sound Russian. While in the process of reforming the Russian monetary system, Tsar Peter I fixed the production of silversmiths to four standard silver purites: 96, 90, 84 and 62 zolotniki. A zolotnick is an obsolete Russian weight measure.
