Marveling at the rows of diamond pavé—40 carats in all—on this black leather collar by Karl Lagerfeld, made in collaboration with Net-a-Porter, you might miss the obvious, a giant 22-carat emerald smack in the middle. Though hydrothermal (synthetic), it’s still a gobsmacking hunk of green, and still an emerald.

One-of-a-kind (literally—exactly one has been made), the haute bauble takes after Lagerfeld’s trademark high collars and will retail for upwards of $37,000, buyable starting today but deliverable only after it’s exhibited at Masterpiece London (June 28 – July 4), a fair of all things super high-end. It also comes with a sketch signed by Lagerfeld, as well as a donation to CLIC Sargent, a UK organization benefitting young cancer patients.