From my reading .835 is a silver mark used in Europe for a silver alloy that contains less silver than sterling (which is .925).
The pearls could be imitation. The way the pearls are finished near the clasp, as well as their very uniform appearance, leads me to believe this is the case. There are some very nice imitations out there. Majorica, Mallorca and the like, for example.
You can try the "Tooth test" as an informal test. Rub one of the pearls against another (but wipe grime off first with a damp soft cloth.)
Genuine nacre feels gritty when rubbed this way, while imitation pearl coating feels smooth.
Edited to add: I have stopped recommending rubbing pearls against teeth (“Tooth test”) Teeth are harder than pearls and can scratch them.