To match the necklace worn to the National Service of Commemoration, Kate donned these earrings.
I cannot find a stock photo from the company, but What Kate Wore managed to grab this Instagram shot from G. Collins and Sons page.
It looks like Kate’s earrings were customized from the design on the left. A triad of diamonds tops off the earrings, but Kate’s pair lacks the additional diamonds.
The earrings are made of pear shaped, faceted tanzanites encircled with small white diamonds, framing the tanzanite. It looks like this is worn as a stud earring, with the post attached directly to the earring. It could also be a clip-on.
These earrings are not for sale to the general public, but Kate’s Closet features some great replicas.