They may look centuries old, but in fact jewellery made with rose-cut diamonds in the Netherlands continued until the early twentieth century. Which does not mean to say all of them are relatively new. To the contrary.
The oldest jewellery made with this special cut of diamond in The Netherlands date back to the 16th century. In fact, Amsterdam became renowned for having the best diamond cutters in the world. Even the Koh-i-Noor and the Cullinan were cut in Amsterdam.
In the 18th century the brilliant cut diamond was introduced. Having many more sides to the cut, their brilliance far out-sparkled the rose-cut. But In The Netherlands people stuck to the sobre glimmer of the foil backed rose cut diamond.
Why was that, you may wonder? Well, at the cutter centres the diamonds were split. The larger, full cut stone found their way to the wealthy French and English buyers, but the thin slivers of diamonds had no purpose. That's why the rose-cut was invented. The slivers were set onto foil so that those stones had a brilliance to equal their bigger siblings and could be sold asthough more valuable.
But that is not the entire story. In The Netherlands being a predominantly Calvinist Protestant country, sporting your wealth overtly, was frowned upon. But it's difficult to stop oneself, isn't it? Some embellishment is imperative. So how does one go about wearing diamonds, without showing off?
You guessed it. The modest glimmer of the rose-cut diamond was deemed acceptable in church going circles. Hence its age long popularity.  Some protestant cities even made the foil darker, almost black, so as to diminish every hint of lustre.
Alternatively, these rose-cut diamond jewels became such a popular type of jewellery itself, they are now extremely sought after.  
This early- to mid-19th century pendant has elaborate patterns of flowers and leaves. The diamonds are all rose-cut and varying in shape and size. There is one big sun-flower like bloom in the middle, surrounded by a bouquet of other flowers in different stages of bloom and leaves.