GUIYANG－Fossil restoration in the mountains requires a variety of techniques except for speaking skills－the more silent you are, the louder you will hear a stone "talk".

For Li Gang, a fossil restorer at a national geological park in Southwest China's Guizhou province, an easily ignored piece of rock might be able to convey a story dating back 220 million years.

The area was beneath the sea between 410 million and 350 million years ago. In 2006, fossils of marine reptiles and sea lilies, with a history of 220 to 230 million years, were unearthed in Guanling county. To better protect and preserve the fossils, the local government established the Guanling Fossil National Geopark, which collects and exhibits fossils of ancient marine creatures.

In his office, Li carefully places a plate-size fossil of a sea lily in a transparent container and uses sophisticated equipment to remove dust from the fossil.

"The sea lily is an animal－a kind of echinoderm to be precise. But it looks like a plant, which is why it has a plant's name," says Li.

As the surface dust clears out, the fossil begins to show more exquisite stripes and a clearer shape of the sea lily's structure.

"The force used in fossil restoration really matters. It should help remove impurities, and also avoid damage," says Li.

His work as a fossil restorer began 20 years ago after a chance encounter with a sea lily fossil.

"I was instantly enchanted by its exquisite look as if it was telling me (about) a mysterious past," Li says.

But at that time, due to a lack of restoration knowledge and skills, "fossil raiders" often destroyed the fossils they stole. Given this, Li began advocating for scientific restoration among local villagers.

"Each and every piece of fossil is unique, which allows for no carelessness," he says. "The restoration of sea lily fossils requires extra care as their skins are as tender as those of humans."

Initially, it took Li more than 10 days to restore a palm-size sea lily fossil. However, he needs around an hour now, as his techniques have improved.

Li has shared his findings with some others in the field. In 2018, he was nominated as an "outstanding contributor" by the China Fossil Preservation Foundation for his devotion to fossil preservation and protection.

The park, which was designated as a teaching base for popularizing geological knowledge in 2009, has held activities to encourage visitors to try fossil restoration with experts.