How Do I Tell My Husband I Don’t Want Any More Pearl Necklaces?

My husband’s recently got into the habit of giving me pearl necklaces.
The first one was a real surprise, but he’s now given me 17 in the last month and it’s getting totally out of hand. My jewellery box is overflowing and it’s not like I can wear more than one at the same time.
It’s obviously a matter of pride that he’s able to provide for me this way, but should I start dropping hints I want some diamond earrings instead?