This double 'knop' brooch is 1 3/4" by 7/8" and tests as silver (I have not nailed down the fineness). The knop design is similar to but not exactly like the Zeeuwse knop pieces I have found online (Dutch in origin...@AnyJewelry). This design configuration is a little different though. And it has an affixed tag marked Tchecoslovaquie (Czechoslavakia) on the back. Would this still be a 'Zeeuwse knop' piece? What might the time frame be? Your thoughts...? Thanks for looking!
This is a 'Tsjechische knop'. (A Czech button.) Zeeuwse means from Zeeland, a province in the southwest of The Netherlands. It is used in other parts of country as well, but never as much as in Zeeland. A Dutch Zeeuwse knop or knoop is slightly more intricate, but the general idea of your brooch is similar to the Zeeuwse knoop. The design appears in slightly different variations in several parts of Europe. But nowhere as beautiful as in the Netherlands, of course. Some examples of Zeeuwse knopen: They are commonly used as collar buttons or trouser buckles: Small ones on pins to secure lace caps, either to a smaller cap underneath, or to a precious metal brace around the head called an 'oorijzer': On a brooch they are always an uneven number, unlike your Czech brooch: The back of a Zeeuwse knoop is closed with filigree:
I don't know how the Czechoslovakian brooch was worn, but the Dutch collar buttons are actual buttons, that go through big buttonholes and are connected by a short chain. Here is a silver pair from my collection: A male friend used to borrow them to wear on special occasions. In other parts of the Netherlands the men used to wear silk neckerchiefs and wear a small brooch on it. Jewellery for men was normal, as it should be. Here is one from the province of Groningen, in the north. It has two coral cabochons and a natural pearl: It looks big now, but is ca 3 cm wide. I took the photo when I got it years ago, in the meantime I have removed the verdigris. It is 835 silver, just like the buttons.