On March 18, 2017, Kate debuted these dainty earrings in Paris.

From the website: “Designed by Louis Cartier in 1924, the Trinity ring is a signature design of the Cartier Maison. The three interlaced bands in pink, yellow and white gold symbolize love, fidelity and friendship. The ring has inspired the full Trinity collection, a timeless testament to life’s most memorable loves.
Trinity de Cartier earrings, 18K white gold, 18K pink gold, 18K yellow gold, each set with 1 brilliant-cut diamond of 0.04 carat.”
Here they are on Kate:

These cost $2,040.