“Moving and booming.” That is how Rahul Kadakia, international head of jewelry at Christie’s, describes the sale of jewelry at auction, with individual pieces routinely crossing the eight-digit barrier. “A decade ago, you’d only hear these numbers in pictures sales; a Picasso sold for $10 million, a Van Gogh for $20 million,” he says. Robb Report sits down with Kadakia to break down the trends. (christies.com)

Robb Report: What have been the past year’s most significant jewelry sales?

Rahul Kadakia: Last…