'Antiques Roadshow' guest stunned to find out that white stones on her brooch were real diamonds

The guest had no idea when the brooch belonging to her great-grandmother had been made.

PUBLISHED JUL 24, 2025

The owner's reaction after the expert appraised it (Cover image source: YouTube | Antiques Roadshow)

It isn't unusual for guests on "Antiques Roadshow" to be unaware of the true value of items that they own, since not everyone can be an expert. But to think of diamonds simply as white stones for years takes things to another level. The realization was shocking for a guest who brought a brooch that belonged to her great-grandmother. The expert Geoffrey Munn revealed to the guest that her brooch was actually studded with real diamonds, and asked her to brace herself before valuing it at $12,000.

Although the woman had assumed that her brooch was made in the 19th century, Munn clarified that it was a 20th century design. After inspecting the piece of jewelry further, he pointed out that it was Art Deco, and the diamond also had a black deposit within, which was carbon that hadn't crystalized. Munn did spot some damage, but reassured the guest that it wasn't too bad, and that the brooch just needed some cleaning.

Finally, the expert came down to business and told the guest to brace herself, as he mentioned that such a piece of jewelry would be worth $12,000 in a store today. The woman was astonished and simply said, "good god," before mentioning that she "didn't think those were diamonds" on the brooch.

While the guest in this case thought of diamonds as stones, in another episode, an expert valued plastic accessories at $11,000. The guest had brought three purses and a bracelet made of plastic. However, it wasn’t any ordinary plastic. It was an early form of plastic, which the expert, Kathleen Guzman, called phenol formaldehyde.

The guest said that she loved collecting purses that had an Art Deco design, and these purses, as per the expert, were quintessential Art Deco-style items. The guest also said that she had more such purses at home, but believed that these were the best. The items were made from the first synthetic plastic called Bakelite. A man named LH Baekeland came up with the formula and had it patented in 1908.

Guzman said that the purses in front of her were worth $500 to $1,500. This was welcome news for the guest who wasn’t perhaps expecting them to be worth so much money.

Then there was a bracelet, also made of Bakelite, which was given to her by her mother. The guest revealed that her family had been close friends with an elderly lady, who was also their neighbour. After she passed away, that bracelet was what the guest’s mother could take and later gave it to her daughter.

This bracelet didn’t look like it was anything special, even though the design on it was truly impressive. The guest said that it was a classic Bakelite design called the Philadelphia bracelet. “And I’m gonna say conservatively, it’s worth between $6,000 and $8,000," the expert revealed.