In a quiet village in southern Jiangsu Province, China, 45-year-old Li Daming never expected that a routine cleanup of his ancestral home’s cellar would turn his life upside down. What he found buried under a pile of old bricks—a small, intricately carved wooden box that emits a faint blue glow in the dark—has not only baffled locals but also drawn the attention of cultural relic experts, who estimate its value at no less than 3 million yuan (approximately $415,000).

Li’s ancestral home, a gray-brick courtyard house built in the late Qing Dynasty (1636–1912), had been vacant for over 20 years. Earlier this year, Li, who works as a construction worker in Shanghai, decided to renovate the house so it could be used as a holiday home for his family. In early June, while clearing out the damp, dusty cellar—an area his grandparents once used to store grain and pickled vegetables—he noticed an unusual indentation in the earthen floor.

“I was moving a stack of rusted iron buckets when my shovel hit something hard, not the usual soil or rocks,” Li recalled. “At first, I thought it was an old pottery jar, but when I brushed away the dirt, I saw a wooden corner with carvings. I dug deeper, and after about an hour, I pulled out a box wrapped in tattered linen cloth.”

What surprised Li most was not the box’s elaborate carvings of phoenixes and peonies, but its strange glow. That night, when he placed the box on his bedroom table, he noticed a soft, cool blue light seeping through the gaps in its wooden joints. “I thought my eyes were playing tricks, so I turned off all the lights. The glow got brighter, like moonlight trapped in wood. I didn’t dare touch it again that night—I even put a towel over it, worried it might be dangerous,” he said.

Upon closer inspection, the box, which measures 30 centimeters long, 20 centimeters wide, and 15 centimeters tall, revealed more intriguing details. Crafted from a dark, dense wood that experts later identified as “golden nanmu”—a rare species native to southern China prized for its durability and resistance to decay—the box’s surface is covered in delicate openwork carvings. On the lid, two phoenixes with outstretched wings are carved in high relief, their feathers so fine that individual strands are visible. Around the sides, peony blossoms and vine patterns wind together, creating a seamless, flowing design.

The source of the glow remained a mystery until experts from the Jiangsu Provincial Institute of Cultural Relics and Archaeology examined the box. Using ultraviolet light and microscopic analysis, they discovered that the wood had been infused with a special mineral powder during its crafting. “The powder contains traces of fluorite and phosphorite, which are naturally luminescent,” said Dr. Zhang Wei, the lead archaeologist on the team. “But what’s remarkable is how the craftsman embedded the powder into the wood’s fibers. This technique was used in royal workshops during the late Qing Dynasty, but it’s extremely rare—we’ve only seen it in a handful of imperial artifacts.”

Inside the box, Li and the experts found even more surprises: a roll of yellowed silk paper with calligraphy written in traditional Chinese characters, and a small jade pendant carved into the shape of a longevity lock. The calligraphy, which experts dated to around 1905, turned out to be a letter from Li’s great-great-grandfather, Li Qingyuan, to his son. In the letter, Li Qingyuan, who was a wealthy merchant trading in silk and tea, wrote about hiding the box in the cellar to protect it from bandits and soldiers during the chaotic years of the late Qing Dynasty. He mentioned that the box contained “a family heirloom worth more than silver” and urged his descendants to “keep it safe until the time is right.”

When asked about the box’s value, Dr. Zhang did not hesitate. “First, the golden nanmu alone is extremely valuable—large pieces of old golden nanmu can sell for tens of thousands of yuan per cubic meter. Second, the craftsmanship is top-tier; the carvings are clearly the work of a master artisan from the imperial workshops. Third, the luminescent technique and the historical letter inside add to its uniqueness. Combining all these factors, we estimate its market value at between 3 million and 3.5 million yuan.”

The news has made Li a local celebrity, but he says he has no plans to sell the box. “My great-great-grandfather hid it to protect our family’s heritage, not to make money,” Li said. “I want to pass it on to my son, just like it was passed down to me. Maybe one day, we can donate the letter to a museum so more people can learn about our village’s history.”

For experts like Dr. Zhang, the discovery is more than just a valuable artifact—it’s a window into China’s recent past. “Many old houses in rural China hold hidden treasures, not just in terms of money, but in terms of history,” he said. “This box tells a story of a family’s survival during a turbulent time, and it reminds us that our cultural heritage is often closer than we think—sometimes, it’s just waiting in a dark cellar, glowing softly, for someone to find it.”

As for Li, he now spends his weekends at the renovated ancestral home, often sitting in the cellar where he found the box, thinking about his ancestors. “Every time I look at that box, I feel like I’m talking to my great-great-grandfather,” he said. “It’s not just wood and carvings—it’s our family’s story, glowing bright after all these years.”