Perth: On Sept. 27, a rare pink diamond ring worth $577,000 was stolen during a viewing day at an auction house, according to a statement from police in New South Wales, Australia.

Local news reports say the pink and white diamond ring, which held a rare pink gem excavated from Australia’s Argyle mine, was snatched from a counter during a “public viewing day” at Theodore Bruce Auctions in Sydney. One hundred people were said to have attended.

The auction house did not return a request for comment. But a spokesperson told 9news: “The opportunity of moving this piece on will be extremely difficult due to the unique design and rarity of the pink diamonds, and we make the genuine offer that should the person or persons unknown who took the ring return it, there will be no questions asked.”

Each of the diamonds in the ring is laser-inscribed with a serial number, said the police statement, which asks anyone with information to contact the department.

A store employee noticed the item was missing and notified police. The ring was the highest-valued item up for sale and the only piece believed to have been stolen that day.