Once you told me it was Dutch, being Belgian, I easily tracked it down. I'll give you an English resumé. First of all, let me tell you that the state these coins are still in, is pretty good !
They were made between 1681-1691 in the Dutch town of Utrecht. It's from an area in Holland called Gelderland. Due to it's specific inscriptions, this is an early piece. Writing on one side 'CONCORDIA:RESPARVÆ:CRESC UNT' (small things grow through unity)
Writing on the other side : 'MO:NO:ARG:ORD:GEL:ET:COMZVT' : new silver coin from the state Gelderland and the count of Zutphen
Material: silver (0,583)
Weight: 4,71 gr
Here's the whole thing (newer piece, so other writing on 1 end) :