Jeweler’s diamond sparkles in the dark

Photo Courtesy of Disinger & Kruger Jewelers
The Night Glow Diamond.

Herald Staff Writer

HUNTINGBURG — In a darkened closet, a bright blue glow emanated from a ring in Bill Disinger’s hand.


The Huntingburg jeweler was demonstrating his prized invention: the Night Glow Diamond. Disinger of Disinger & Kruger Jewelers, along with diamond cutters in Tel Aviv, recently created a gemstone which can actually glow in the dark for up to eight hours in the buyer’s choice of two colors.

So far, the product has mostly been sold locally as Disinger worked through a complicated patent process to secure the design. The Night Glow went on the local market about a year ago, but now that the patent is nearly complete, Disinger plans to open sales to a wider area.

He owns three patents on the product, which uses a special cutting procedure along with a photoluminescent membrane to absorb and reflect light and create the glowing effect. There have been many attempts to invent such a gem, but this is the first successful version.

“There were so many hurdles that we kept going over,” he said. “The first one was, could it even be done?”

There is a market for glowing gems as many customers have complained to the jeweler that their diamonds are invisible once the sun goes down.

“A lot of people have been really interested in it simply because if you think about it, diamonds have scintillation in light all during the day, but when it gets dark, and you’re wearing an engagement ring or something, you can hardly see it,” Disinger said.

He eventually convinced his cutting team in Tel Aviv to run some simulations on an Israeli military computer which showed that, by carving very specific angles into the stone, they could allow light to pass all the way through the diamond. Even once the computer had confirmed that the process was possible, it took much determination to bring the diamond to life.

“When we first did it, it worked, but very slightly,” Disinger said. “So we had to keep tweaking it and tweaking it until we got a very uniform color all the way around.

“Typically light bounces into the diamond and back out the top. What we wanted to do was continue to have that bounce effect, but we wanted the light to also be able to go down through the diamond and then reflect back up off of a membrane. It’s like a mirror.”

The principle of Disinger’s ocular cut is similar to that of using a magnifying glass to amplify the sun’s rays and catch a piece of paper on fire.

When the membrane and diamond are oriented and cut in a certain way, the light is magnified to an intense point which excites molecules in the membrane. So far, Disinger has created sea foam green and Caribbean blue membrane options and is currently working on a red color.

The diamond will absorb light from the sun and from indoor lights during the day so it is ready to glow once evening arrives. Disinger is also developing a pen flashlight which will emit the exact color of light to optimize the glowing effect on the diamond.

The jeweler offers different head options for rings and also sells pendants and earrings with the Night Glow. A basic half carat costs $3,900.

Contact Claire Moorman at

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