Forget rhinestones. The D Diamond New York is redefining luxury pet jewelry with solid 18K gold and diamond dog collars that cost up to an eye-popping $80,000.

Yes, real diamonds for dogs are officially a thing. Here’s why luxury pet jewelry is suddenly everywhere.

Twila True, in collaboration with Izzy the Frenchie, launched a pooch-friendly jewelry line. At left, colorful Pearl (@misbadasspearl) models the most expensive piece in the collection. Brad Zangwill ...