Kate has been photographed wearing these earrings after her April 2011 wedding.
According to What Kate Wore these are believed to be part of a wedding gift from Prince Charles.
This does seem plausible to me. I have not been able to find these for sale to the public from any jewelry company, which makes me think these were custom-made for Kate. Another thought I have is that these earrings don’t seem to match Kate’s taste in jewelry. They look a bit too clunky and irregular to be chosen by Kate herself. Most of her jewelry (at least what she has worn since the engagement announcement) has a clean and smooth design. For these reasons, I agree with others who believe that these earrings must have been a wedding gift.
The earrings feature a length of diamonds: at the top is a round diamond surrounded by smaller diamonds to frame the center diamond. The earring’s center features three baguette shaped diamonds, then the line of gems is finished off with another round diamond surrounded by smaller diamonds (identical to the top diamond drop). It looks like it is set in white gold.
Kate notably wore these when she was in Canberra.
Given what I have already stated here, I do not have a link for a company’s website or a price tag. However, there is an Etsy seller who has created a pair inspired by these earrings.