Great point. Here is a South Sea Pearl necklace we made that has roundels between each pearl. Although the pearls are larger and the roundels are larger, I think you can get the idea.
AmericanPearl.com has a section dedicated to roundels here at this link:
Order a Pearl Necklace with Diamond Rondels We have hundreds of different style rondels in stock so if there is something you would like that you don't see, please join the Pearl-Education.com forum and send us an inquiry as we can custom make anything.
This is a close up of what it looks like:
Here is a necklace that has rondels every 2nd pearl going all the way around in white gold:
And another gorgeous necklace with roundels every 4th pearl in yellow gold going all the way around: