On July 20, 2017, Kate attended a reception in Berlin, Germany. She wore this bracelet that once belonged to Diana.
At first, some of us bloggers believed this was Kate’s years old bracelet. But close inspection revealed spacers on this one that her own bracelet lacks.
Diana famously wore this bracelet with her “Elvis” gown”.

The full story behind it can be found here.
The bracelet is made of three strands of white pearls, and at least six diamond halo spacers. From what is visible in the photo there are at least two rows of diamond spacers on the bracelet, three spacers on each row.
Here it is on Kate.