You'll find few high-carat collars for contemporary cats, but ancient cat jewels go for thousands, dating to a time when we worshipped at the feet of the cat goddess.
You can buy diamond dog collars for $150,000, but bespoke dog ornament is nothing new. Nineteenth-century London was full of eccentric dog owners who loved to walk their pups around in bespoke collars and high-karat dog collars date to antiquity.